Return to Strength of Victory

Posted by Vince on August 25, 2008 | permalink | 0 comments

We noted that margin of victory is a poor indicator of strength of victory. The problem is that a late score in a game can make the it seem closer (or not as close) as it really was. GridIronMine calculated the strength of victory of all games using its Victory Forecast.

The above graph plots the final point differential--the margin of victory--against the average VF for the game--the strength of victory. The margin of victory ranges from 1 to a maximum of 46 points (New England over Buffalo). On the other hand, strength of victory ranges from 25.1% average VF (Dallas over Detroit) to 92.6% (New England over Buffalo). While the plot shows that there is a general trend the correlation not high. For example, consider that Cleveland beat visiting Baltimore by 14 and KC also won at San Diego by 14. Cleveland lead by at least two touchdowns for more than 50 minutes, and by 21 before giving up a meaningless touchdown (that increased the Raven's VF from 4% to 6%) in the fourth quarter. In contrast, the Chiefs led for only 12 minutes (and trailed for 34 minutes), but it was the last 12 minutes while scoring the last 24 points of the game. While point differential considers both games equivalent, strength of victory grades Cleveland at 90% and KC at 39%.

The above analysis does not consider the quality of opponent. San Diego was one of the top teams, so KC's performance should be consider better than the same performance against an average (or below average) team. Similarly, Baltimore was below average, so Cleveland should be given less credit for its performance. This leads us to create opponent adjusted strength of victory measure. The table below that shows this for the 2007 regular season.

There is little surprise that the top team is New England. The first surprise is that Washington comes in at number 5. That rank is 7 positions higher than their rank by win-loss percentage. The reason is that Washington was competitive in most of their 7 losses, having second-half leads in 5 of them. Additionally, the Redskins had a 6 wins that were better than average. The team with the largest increase from rank by win percentage to rank by SoV is Chicago, 8 positions from 18 to 10. The argument can be made that these teams are better than their records indicate.

On the other side of the coin, San Francisco edges out Miami for last place. Nine of the 49ers 11 losses were below average, 4 were romps, while all 5 wins were below average. There are several teams that have much better win-loss ranking than SoV ranking. Cleveland has the 7th best win percentage, but ranks 19th in SoV--a whopping 12 positions lower. While the Browns had 10 wins, 2 of their 3 quality wins were against the bottom two SoV-ranked teams: San Francisco and Miami. They were blown out in 2 games. Moreover, they played only one team in the top third of SoV, while 6 games and 5 victories were against bottom-third teams. Carolina and Arizona also had double digit differences in SoV and win-percentage rankings. The argument can be made the these teams are not as good as their records indicate.

Strength of Victory

Posted by Vince on March 5, 2008 | permalink | 0 comments

The final point spread is not the best indicator of strength of victory. For example, Houston dominated Oakland last year but only won by 7, 24-17. The Texans scored on their first possession and led for the last 52 minutes. They led 17-0 at half and had a 14-point lead until Oakland closed it with a touchdown with 90 seconds remaining that was set up by an awful 10-yard punt.

On the other hand, Chicago won 27-20 in Green Bay, in a game the Packers gave away. The Packers scored on their first possession and lead for 54 minutes. However, Chicago scored 20 second-half points, include 10 in the fourth quarter. The game winning touchdown broke a tie just before the two-minute warning.

While both of these games ended with a margin of victory of 7 points, the Houston victory was clearly stronger then that by Chicago. The GridIronMine Victory Forecast (VF) system offers unique way to evaluate the strength of victory. VF computes the likelihood of victory after each play. If we consider the average VF for the entire game we get a better idea of the strength of victory. Houston's victory comes in at 82.3% average VF, which is the 45th best VF, while Chicago registers 35.2%--the 8th worst victory in regulation.

Below we list the top ten most dominating and least impressive victories of the 2007 season. (All statistics are for non-overtime games.) First, let's get a perspective on VF. Victories ranged from 94.4% to 25.1%. Half of the victories were 71.7% or better. In only 48 games was the winner's average VF less than 50%.

Stomps

Now the top ten biggest stomps.

Game	Margin of victory	Average VF %
		Game	4th Quarter	Last 5 mins
IND 44 @ BAL 20	24	94.4	99.0	99.0
MIN 27 @ SF 7	20	92.8	97.4	99.0
NE 56 @ BUF 10	46	92.6	99.0	99.0
DET 14 @ SD 51	37	92.5	99.0	99.0
ATL 3 @ TB 37	34	92.3	99.0	99.0
NE 49 @ MIA 21	21	92.1	98.9	99.0
SD 14 @ NE 38	24	92.1	96.9	99.0
PIT 34 @ CLE 7	27	92.0	98.8	99.0
OAK 11 @ JAC 49	38	91.6	99.0	99.0
KC 7 @ DEN 41	34	91.3	99.0	99.0

The number one stomp of 2007 is Indianapolis over Baltimore in week 14. The Colts scored touchdowns on their first four possessions, including a safety on a blocked punt. After 18 minutes of play, they hold a commanding 30-point lead--with a VF of 99%. The second biggest stomp is the Vikings 20-point victory over the 49ers also in week 14. This surprising because there are 23 games with larger victory margins that have a lower average VF. This game is justifiably the second ranked because the Vikings jumped to a 27-point lead in just 21 minutes. While they failed to score again, their VF never slipped below 95%--even after the 49ers lone score midway through the 3rd.

Unsurprisingly, the Patriots appear three times in the list: beating Buffalo 56-10, Miami 49-21, and San Diego 38-14. Interesting New England's 52-7 throttling of Washington in week 8 checks in at number 25 with an average VF of 86.5%. Although this is the second largest margin of victory, the lead was in single digits until almost midway through the second. While it was a true stomp in every sense of the word, there were 24th bigger stomps.

Snatching victory from the jaws of defeat

No doubt teams and die-hard fans love stomps, but the other end of the scale has the more exciting games.

Game	Margin of victory	Average VF %
		Game	4th Quarter	Last 5 mins
DAL 28 @ DET 27	1	25.1	25.2	20.1
DAL 25 @ BUF 24	1	25.3	14.9	8.8
BUF 17 @ WAS 16	1	30.3	32.2	32.4
CLE 28 @ PIT 31	3	30.6	49.2	68.0
NYG 21 @ CHI 16	5	30.9	34.9	58.9
SEA 24 @ STL 19	5	31.9	54.6	71.4
MIN 10 @ KC 13	3	33.9	61.5	81.0
CHI 27 @ GB 20	7	35.2	58.7	71.0
NYJ 31 @ CIN 38	7	36.6	71.0	95.4
NYG 24 @ WAS 17	7	37.0	59.8	82.5

The two weakest victories in 2007 were last-second comebacks by the Cowboys. On the road against Detroit and Buffalo, Dallas eeked out a 1-point victories with last-minute touchdowns. Against the Bills, the Cowboys scored twice in the last 20 seconds for a very improbable victory. The Cowboys' VF average only 8.8% in the last five minutes. This means the Bills averaged 91.2% and some how lost! The Super Bowl champion Giants have two games in the bottom 10. In both games, New York scored a pair fourth-quarter touchdowns.

Interestingly, both of Pittsburgh's victories over Cleveland made our lists. The first game is 8th biggest stomp and the second was the 4th weakest victory.

We want to re-iterate that point spread is not the best indicator of strength of victory. Although the three weakest victories are one-point victories, only half of the one-point victories are in the bottom ten. The other three come in at 11, 17, and 62 from the bottom.

A better measure for strength of victory

Fans have always understood that final margin of victory does not always give the true picture of the game. The novel Victory Forecast system from GridIronMine provides solid information to show this and completely new and refreshing way to look at the strength of victory. We think that average VF is a clearly superior way to evaluate the strength of victory.

At the end of the day, all victories are the same. And in fact, it may be that the team that wins games that it did not dominate, is the best team. Witness the Giants two fourth-quarter rallies. In upcoming columns we will look into strength of victory by teams for this season.

Was Belichick's decision justified?

Posted by Vince on February 4, 2008 | permalink | 0 comments

Bill Belichick is one of the most analytical coaches in the NFL. He is also one of the most successful. Yet, nearly everyone thinks he made a big mistake in the third quarter of Super Bowl XLII.

The situation is 6:49 to go in the third ahead 7-3 with a 4th and 13 on the Giants' 31 yard line. The decision is to kick a field goal, punt, or go for the first down. Brady threw an incomplete pass over Jabbar Gafney's head.

Let's use GridIronMine's Victory Forecast (VF) to evaluate this situation and determine whether Belichick's decision to go for the first down was justified. First, we must determine the VF of the various situations. (BTW, in the current situation NE has an 79.8% VF.) We start with the field goal. If the field is good, the VF increases to 83.2%. If missed and spotted at the 38, the VF is 74.0%. (For simplicity we exclude low probability outcomes, such as a blocked field goal and a roughing-the-kicker penalty, that do not have much effect in the final analysis.)

Next, is the punt. This more complicated because there are many more possible outcomes. Barring any unusual event, the worst case is the Giants will take over on the 20, the best is inside the 5. The VF for the worst case is 76.8%. It is 79.1% if the Giants take over on the 5.

The last situation, going for the first down, is the most complicated. Again, we do not consider unusual cases like a pick-six or a roughing-the-passer penalty. The most likely failure case is an incomplete pass, yielding a VF of 75.2%. A successful conversion will be between 13 and 31 yards. Let's suppose the average conversion is a 15-yard gain. This increases NE's VF to 86.7%.

Here is a summary so far.

	Victory Forecast
Situation	Worst case	Best case
FG	74.0	83.2
Punt	76.8	79.1
Pass	75.2	86.7

So an overly pessimistic person would punt because it has the best worst-case VF, whereas an overly optimistic person would pass because it has the best best-case VF. However, a rational person must weigh the good and bad. To do that we need to know the likelihood of these outcomes. For example, to evaluate the choice of a field goal, we need to know the probability of kicking a 48-yard field goal. Gostkowski has not kicked enough 48-yard field goals to use only his statistics. The GridIronMine VF estimates the NFL average as 58%. It is not clear what Gostkowski's probability is, so we compute the result of an attempted field goal for several values. The field goal VF is calculated as:

   probability x best_case_VF + (1 - probability) x worst_case_VF
   

Probability	VF
0	74.0
10	74.9
20	75.8
30	76.8
40	77.7
50	78.6
60	79.5
70	80.4
80	81.4
90	82.3
100	83.2

The current VF is 79.8% (and of course a successful field goal raises the VF and missed field goal lowers it). Interestingly, on average attempting to kicking the field goal will lower a team's VF. This does not mean it is a bad idea to try to kick a field goal, just that it is a bad situation to be in.

The above table shows that punting is not a good idea. The best-case punt is about the same as a field goal with a 54% chance. That means best-case punt is better if the field goal will be made less than 54% of the time. On the other hand, the worst-case punt is about the same as a field goal with a 29% chance. Basically, in this situation at this time of the game, punting is a worse choice than kicking a field goal. (Later in the game there is a different story.)

So now we turn our attention to going for the first down. We must look at the probability of converting. There are not enough 4th and 13 situations, so we consider 3rd and 13 as well because teams are trying to get all 13 yards on either down. Also, one or two yards difference probably doesn't change the play call. So we look at the 3rd and 4th downs with between 11 and 15 yards to go (excluding weird time-crunch situations at end of each half). NE had this situation on 3rd down 21 times and converted 5 times. They had 8 4th down situations and attempted none (before the Super Bowl). Thus, NE has an 23.8% average conversion this season. Of course, that was not against the Giants and was not in the Super Bowl. Teams converted 21.1% of their 3rd and long situations against the Giants, which is almost exactly the NFL average of 21.0%. None of this data tells us the precise probability of a conversion. So once again, we look at several conversion probabilities. The VF is calculated in the same way as for the field goal table.

Probability	VF
0	75.2
10	76.4
20	77.5
30	78.7
40	79.8
50	81.0
60	82.1
70	83.3
80	84.4
90	85.6
100	86.7

Using the last two tables, we can evaluate the choice between a field goal and a pass. It is a push (neither choice is better) if we choose best-cases (or worst-cases) from each table. For example, 66% field goal chance is essentially the same as 42% conversion. To make the case against Belichick one has to suppose that Gostkowski will make the field goal at higher than the NFL average (say 62% for a VF of 79.7%) and NE will convert at less than their season average (say 18% for a VF of 77.3%). In this case, the decision was only 2.4% VF worse. That is not a large VF change. For example, the previous play (a sack) cost the Patriots 5% VF. Interestingly, supposing NE had a 0% chance of converting and a 100% chance of making the field goal, the decision to go for it has a VF 8% worse than kicking the field goal. This last fact shows how close the call really is.

Note: This analysis would be different if the score were different. For example, if Patriots led by 6 points or trailed by 2 the field goal would have a greater value, making going for it less justifiable.

The above analysis makes many assumptions. One can argue against these and provide other assumptions. However, unless the new assumptions are significantly different, the new analysis will be similar. Basically, Belichick made a reasonable and easily justifiable decision.

Side note

We had assumed that NE was the best, or nearly the best, third-down team in the league. In gathering data for this article, we were surprised to find that NE is a pedestrian 63rd percentile (12th best) at converting third and long. Below is the data for 3rd and long (11-15 yards) not including situations at the end of each half.

team	conversions	attempts	rate
SD	12	27	0.444
CIN	8	20	0.400
NO	5	14	0.357
DEN	9	27	0.333
JAC	9	30	0.300
WAS	6	21	0.286
NYJ	8	28	0.286
IND	5	18	0.278
CLE	5	19	0.263
PHI	5	20	0.250
OAK	8	33	0.242
NE	5	21	0.238
NFL	157	746	0.210

Update

Some have commented that this article doesn't justify Belichick's decision.
In which case, the original title ("Belichick's decision was justified") was misleading. We have edited the title. This article has had some typos fixed and we extended the range of two tables.

Giant Upset

Posted by GridIronMine on February 4, 2008 | permalink | 0 comments

This article appears in the Patriots Football Weekly and PFW online. The VF percentages quoted in this article refer to the graph presented in the hardcopy of the PFW, which uses team-dependent VF. The online tools use the team-independent (or NFL average) VF.

(click to enlarge)

The Patriots started the Super Bowl as a similar favorite as in their previous two playoff games. GridIronMine's Victory Forecast (VF) system at the opening kick showed the Pats as having an 85% chance of winning.

The Giants moved the ball on a long drive down to the Pats' 17 and had a first down. However, the Pats' red zone defense came through once again, and the Giants had to settle for a field goal and a 25% VF. Then, the Pats, as is typical, marched down the field and scored a touchdown. The key play on the drive was a pass interference penalty on Antonio Pierce on a pass from Tom Brady to Ben Watson, which increased the Pats' VF to 84%. After the score, the Pats' VF was back to 85%, and the second quarter was only a few seconds old.

The story of the second quarter was third down. Several key third down plays had large VF swings. First, Eli Manning was intercepted by Ellis Hobbs on a third down and five at the 14 yard line, for a VF swing of 7%. Next, Laurence Maroney was stopped on a key third and one play, killing a drive and costing the Pats 5%. Then, with the Giants again in field goal range, Ahmad Bradshaw committed an illegal bat on a fumble. While this cost the Giants 7% in VF, the possibility of the Giants losing the ball made it a good play. Finally, the Pats converted a third and 13 on their own 8 yard line on a screen pass to Wes Welker with just 1:35 to go in the half. This followed a questionable time out by Tom Coughlin on the previous play. In particular, GridIronMine would have recommended allowing the clock to run and calling time out if the third down play failed to convert the first down. This would still have given the Giants plenty of time to score before the half, but would have left the Pats with only about 50 seconds left if they did convert. This could have been a very important play, but Justin Tuck forced a Tom Brady fumble on a sack just before the half, killing the Pats' chance for points and increasing the Giants' VF to 21% at the half.

The third quarter did not have many interesting plays. Bill Belichick made an excellent challenge, catching the Giants with 12 men on the field on a punt and increasing the Pats' VF by 6%. However, on the same drive, Brady was sacked by Michael Strahan on third down, and then overthrew Jabar Gaffney on fourth down. Each play cost the Pats 5% in VF. The fourth down play was from the 32 yard line, and the decision was a curious one. In fact, it was similar to the situation in the Patriots/Chargers playoff game in 2006, where Marty Schottenheimer went for the first down in a similar situation (fourth and 10 from the 31 yard line). Because of the final score, Belichick's decision will talked about for ages. However, using several reasonable choices for the probability of converting a field goal or the 4th down, we find at most 2% VF difference between going for it and kicking the field goal. Belichick's decision is completely reasonable and justified, but we suspect few people will see it that way.

The fourth quarter is where the action was. First, Manning completed a 45 yard pass to Kevin Boss, then a third down conversion to Steve Smith, and finally a touchdown pass to David Tyree. These increased the Giants' VF by 10%, 6%, and 8%, respectively, for a VF after the touchdown of 55%---the first time they were over 50%. The Giants even got the ball back, and their VF got as high as 62% before they punted.

Next, Brady led one of his patented fourth quarter drives, which culminated in a 6 yard touchdown pass to Randy Moss. This increased the Pats' VF by 22% to 80%. However, this was to be the Giants' day, as they made several key plays on their winning drive: a 1 yard fourth down conversion (barely) by Brandon Jacobs (11% VF increase), a great catch by David Tyree for 32 yards (27% VF increase), a key third down conversion to Steve Smith (15% VF increase), and the touchdown to Plexico Burress (42% VF increase). The Pats still had an 8% VF after the touchdown, but the sack by Jay Alford made that 2%, and gave the Pats only two desperation passes before the game ended.

Injured Chargers Squander Unexpected Gifts

Posted by GridIronMine on January 21, 2008 | permalink | 0 comments

This article appears in the Patriots Football Weekly and PFW online. The VF percentages quoted in this article refer to the graph presented in the hardcopy of the PFW, which uses team-dependent VF. The online tools use the team-independent (or NFL average) VF.

(click to enlarge)

The Patriots started the AFC championship as a heavy favorite over the Chargers. GridIronMine's Victory Forecast (VF) system at the opening kick showed the Pats as having a 85% chance of winning.

Unlike last week's game against the Jags, this game was more of a defensive battle. In fact, the Patriots did not score any points on their first three possessions. In the 17 previous games, the Patriots scored on their initial possession in 14 games and on their second possession in the other 3 games. Clearly, the Chargers defense (perhaps with an assist from the wind) came to play.

The first key play was the first Tom Brady interception, courtesy of Quentin Jammer. This increased the Chargers' VF from 19% to 27%. Their VF increased to 33% when they had a second and goal at the eight. In what would be the story of the game, the Chargers did not score a touchdown, instead throwing two incomplete passes. The Chargers VF was 27% (6% lower than 2nd down) following the filed goal.

The Chargers' experience in this game within the 10 yard line showed the considerable difference between having first down and goal inside the five versus inside the ten. We discussed this in a previous article; to summarize, our research shows that the chance of scoring a touchdown when starting with a first and goal on the nine yard line is only 53%. Coaches may repeat over and over that you have to score touchdowns in the red zone (true), but a touchdown when starting with a first and goal at the nine is really, over the entire league, is only somewhat likely.

The battle after this point, for the rest of the half, seemed to be one of interceptions. Philip Rivers threw one to Asante Samuel, which increased the Pats' VF by 8% and led to a Pats' touchdown. At this point, with an eight-point lead, the Pats' VF was 89%. Rivers threw another interception three plays into the Chargers' next drive, but this one only decreased the Chargers' VF by 2%, because it was a long pass. It was actually similar to a 35 yard punt (except it came on first down). The Pats had a three and out, punted, and the Chargers drove for a half-ending field goal. The Pats' VF at the end of the half stood at 82%, as they led 14-9.

The second half opened with the Patriots taking possession. However, their first drive ended in a Drayton Florence interception of Brady. This increased the Chargers' VF 7% to 22%. Their subsequent drive netted them at one point a first and 10 at the Pats' 13. While their first two drives ended in field goals, in large part because both contained a first and goal at the nine, this time the Chargers were in good shape. In fact, they had third and 1 at the Pats 4 yard line, and the subsequent 2 yard loss decreased the Chargers' VF from 32% to 25%, a whopping 7%. This is because not only did they not make the first down, but they took themselves out of an ideal time to go for the first down on fourth down by losing two yards. The Chargers had to settle for a field goal, and their VF stood at 25%.

The Pats took the next possession the length of the field, but had an even worse first and goal than the Chargers did; the ball was on the 10 yard line. Their VF went from 82% to 85% after Wes Welker caught a pass to the 2, but Brady threw an interception to Antonio Cromartie on 3rd down, which decreased their VF to 72%. Had Cromartie simply taken a knee in the end zone instead of running the ball out to the 5, it would have been an even larger swing.

The Pats forced the Chargers to punt and marched the ball right down the field for a touchdown and a 21-12 lead. Their VF stood at 84%, and there was just over 12 minutes to go. The Chargers took the ball and had a fourth down and 10 at the Pats' 36 yard line. With just over 9 minutes to go, the Chargers chose to punt. This is despite the knowledge that that Pats have a great offense. Certainly, GridIronMine.com thinks this decision was a significant mistake. The Pats, in fact, held the ball for the rest of the game. The key play on the drive was probably the brilliant driving catch by Faulk on third and 11, which increased the Pats' VF by 4% to 89%. Another conversion to Faulk on a third and three, and the Pats' VF was 96%, and they were on their way to Arizona.

Same Story in the Post Season

Posted by GridIronMine on January 13, 2008 | permalink | 0 comments

This article appears in the Patriots Football Weekly and PFW online. The VF percentages quoted in this article refer to the graph presented in the hardcopy of the PFW, which uses team-dependent VF. The online tools use the team-independent (or NFL average) VF.

(click to enlarge)

The Patriots started the divisional playoff game as a heavy favorite over the Jags. GridIronMine's Victory Forecast (VF) system at the opening kick showed the Pats as having a 85% chance of winning.

The game was an exciting, up-and-down the field game from the start. The first possession of the game went to the Jags, and had two interesting plays. The Jags went for the first down on fourth down and one from the Patriots 43 yard line. We have advocated going for 4th down in these kind of situations this year, especially when facing the Patriots' unstoppable offense. Garrard completed a 34 yard pass to Lewis, increasing the Jags' VF by 6%, to 26%.

This gave the Jags first and goal on the 9, quickly became third and goal at the 8. Garrard completed a pass to Jones for a touchdown, but replays showed that Garrard's left leg was actually on the ground before the ball left his hand. Bill Belichick appeared primed to challenge the call, but the Jags got the ball snapped on the point after and he still had the red flag in hand. This was a rare mistake by Belichick. Of course, it was not certain that the call would be overturned, but it clearly could have been. At that point in the game a touchdown is 13% better for the Jaguars than a field goal.

After the Patriots drove the length of the field to tie the score at 7, Garrard fumbled on the next Jags' series, and Vrabel recovered. This play increased the Pats' VF by 10%, from 76% to 86%, and the subsequent short touchdown drive left the Pats with a VF of 90%.

The Jags tied the score at 14, and then the Pats drove the length of the field again near the end of the first half. But two key plays stopped them from scoring. The obvious one was the missed field goal by Gostkowski, which decreased the Pats' VF by 7%, to 69%. However, the forgotten play was the chop block called on Stephen Neal, which decreased the Pats' VF by 4%. The play changed a third and 6, which the Pats had been making (and continued to make) all day, into a second and 23. This is what really forced the field goal in the first place.

Also forgotten, especially given the way the game was going, was that the Jags did not score given 53 seconds, starting from their 25 with two timeouts. In particular, Garrard missed a pass to Northcutt that would have given the Jags great field position (probably around midfield), which decreased the Jags' VF by 3%, and then it decreased further when they failed to get a first down.

The second half belonged to the Pats. They took the opening kick and marched down for a touchdown. The key play on the drive was not the touchdown, but a 13 yard completion from Brady to Gaffney on 3rd and 3 at the 19. This play increased the Pats' VF by 5%, to 82%.

Next, the Jags tried to respond, down 21-14. They drove to the outskirts of the red zone, and faced a third and 11 from the 21 yard line. Garrard made a perfect pass to Northcutt, but the pass was dropped. It led to a field goal that increased the Jags' VF by 2%, to 22%. However, if Northcutt would have made the catch, the Jags would have had the ball around the 2 yard line. This would have made the Jags' VF 29%. This was perhaps the key play of the second half.

The Pats scored quickly to go up 28-17, and the Jags needed to answer to remain in the game. They drove inside the Pats' 10, but faced a fourth and goal at the 7. Jack Del Rio decided to kick a field goal, which did not change the Jags' VF at all. Additionally, one must take into account when an offense is nearly unstoppable like the Patriots. This makes Del Rio's decision even worse. When the other team's punter is taking the night off, you have to go for the touchdown in that situation. Needless to say, the Jags did not stop the Patriots, as they went right back up by two scores (11 points) on their next possession, effectively ending the game.

Top Ten Plays for 2007

Posted by GridIronMine on December 31, 2007 | permalink | 0 comments

GridIronMine.com looks back at the most significant plays during the regular season

There are no doubt many ways to judge the value of a play. GridIronMine.com uses a mathematically objective and completely innovative model. The significance of a play is determined by the Victory Forecast (VF) model developed by GridIronMine.com.
The model uses modern statistical analysis along with special end-game modeling to calculate the probability of victory for any game situation (point differential, time, scrimmage, down, distance, etc.). These plays were selected based on how much a each contributed to a team's victory (or loss) in term of the change in VF from the start of the play to the end. We ranked the approximately 41,000 plays this season to find the ten most significant plays.

	Change	Before	After	Game	Score	Time	Description
1	78%	78%	0%	Browns at Raiders	Browns trailing by 2	0:00	Raiders block 40-yard field goal
2	72%	1%	73%	Patriots at Ravens	Patriots trailing by 4	0:55	Ravens called for defensive holding on incomplete 4th down pass
3	70%	24%	94%	Titans at Texans	Titans trailing by 1	0:31	Titans pass 46 yards into short FG position
4	59%	34%	93%	Steelers at Jets	Tied	12:00 (OT)	Jets return punt to Steeler's 26
5	57%	23%	80%	Chargers at Packers	Packers trailing by 4	2:03	Packers throw 57-yard touchdown pass
6	55%	43%	98%	Bears at Eagles	Bears trailing by 4	0:09	Bears throw 15-yard touchdown pass
7	53%	98%	45%	49ers at Cardinals	Tied	6:43 (OT)	Cardinals miss 32-yard FG
8	51%	80%	29%	Seahawks at Cardinals	Tied	1:48	Cardinals recover fumble at Seahawks' 46
	51%	12%	88%	Seahawks at Eagles	Eagles trailing by 4	1:16	Eagle return punt to Seahawks' 14
10	50%	48%	98%	Vikings at Broncos	Tied	14:12 (OT)	Broncos recover fumble at Vikings' 12

Surprisingly, less than half of the top ten plays are touchdowns or turnovers. Not surprisingly, all the plays occurred in the fourth quarter or overtime when the game hung in balance. The largest VF change with more than 5 minutes remaining in regulation was 36% on Charles Woodson's fumble return for a touchdown in Green Bay's victory over Washington, which ranked 41st on our list.

The play that had the largest change in VF was a missed field goal at the end of a game. The very reliable Phil Dawson lined up for a very makable 40-yard field goal with 3 seconds left. However, Oakland's Tommy Kelly blocked the kick to steal a win for the Raiders. On this play the Brown's VF changed from 78% to 0%, as a 40 yard field goal is made by the average kicker about 78% of the time.
Another missed field goal made the top ten. Neil Rackers shanked a 32 yard field goal in overtime against the 49ers, which decreased the Cardinals' VF from 98% to 45%. Making a 32 yard field goal is a high probability event, and essentially the game becomes about even money when the Niners took over the ball.

The second most significant play was a penalty, and it was the play that saved the Patriots' perfect season. With 55 seconds left in the game and no time outs left, the Patriots faced a 4th down and 5 on the Ravens' 13 yard line. Tom Brady threw incomplete to Ben Watson, which put the Ravens' VF at 99%---all they had to do was kneel down twice to win. However, it was not to be because of a defensive holding penalty on Jamie Winborne. This decreased the Ravens' VF from 99% down to 27%---a startling change of 72%.

The third largest VF change occurred in the wild Tennessee-Houston game, where the Titans blew a 25 point lead and trailed by a point with 39 seconds to go. They had the ball on their own 37 yard line, but Kerry Collins hit Roydell Williams on a 46 yard pass, which increased the Titans VF 70% from 24% to 94%. Essentially, this play moved the Titans from out of even Hail Mary position into winning FG position.

Two key touchdown passes accounted for large changes in VF. The first occurred when Brett Favre threw a 57 yard TD pass to Greg Jennings against San Diego to give the Packers a 3 point lead with 2:03 to go. This play increased the Packers' VF by 57%. The second was a Brian Griese to Mushin Muhammad TD pass that gave the Bears a 3 point lead with 9 seconds to go and increased the Bears' VF by 55%. The Griese pass increased VF less, but the end result was a 99% VF for the Bears. The Packers still had to stop the Chargers on their last possession, so their VF stood only at 80%. The large increase in the Bears game occurred because the game was essentially over, whereas the large increase in the Packers game occurred because the Packers weren't close to scoring before the TD.

Two punt returns were huge plays. Leon Washington increased the Jets' VF by 59% (to 93%) when he returned a punt against the Steelers (in overtime) for 33 yards to the Steelers' 26 yard line. This play had such a large VF swing because they were now in field goal range in a situation where a field goal wins the game (and furthermore, it was first down, and there was no time pressure). A similar situation occurred when Brian Westbrook returned a punt against the Seahawks for 64 yards. The Eagles were down by 4 points at the time, with little time left, but had a first down at the Seahawks' 14 yard line. This situation is interesting because while Westbook increased the Eagles' VF by 51% with his key return, the Eagles lost the game when A. J. Feeley was intercepted three plays later.

Finally, two fumbles made the list. In a tie game with less than 2 minutes left, Matt Hasselback fumbled the snap when the Seahawks were driving for the winning score against the Cardinals---when they were almost in field goal range---and gave the Cards excellent field position at the Seahawks 46 yard line. This changed the Seahawks VF from 80% to 29%. It means the last field goal will likely be attempted by the Cards instead of the Seahawks; obviously, this is a key play. The second fumble to make the list was when Denver recovered a Tarvaris Jackson fumble on the 12. Jason Elam kicked a walk-off field goal on the next play, ending disappointing seasons for both teams.

We have presented the most significant individual plays of the season. They may not be the most glamorous. Moreover, there are sequences of plays that have together created a larger swing in VF. For example, Dallas went from 7% to 100% in the last two plays against Buffalo, see game. GridIronMine.com's Victory Forecast provides a different perspective on the game-changing plays of the season.

Picture Perfect

Posted by GridIronMine on December 30, 2007 | permalink | 0 comments

This article appears in the Patriots Football Weekly and PFW online. The VF percentages quoted in this article refer to the graph presented in the hardcopy of the PFW, which uses team-dependent VF. The online tools use the team-independent (or NFL average) VF.

(click to enlarge)

The Patriots started week 17 as a 90% favorite over the Giants, according to GridIronMine.com's Victory Forecast (VF) system.

The first interesting play occurred on the first drive of the game. The Giants challenged an incomplete pass on a first down that, if successful, would have resulted in an 8 yard gain to the Patriots 10 yard line. On the surface, this seems like a challenge that should never be made---8 yards, as we have said in past columns, is less than 2%. However, in this case, the difference between second and 10 at the 18 and second and 2 at the 10 is a little over 3%. This is due to the highly desirable situation of having second and 2. Overall, GridIronMine.com feels that this was a marginal use of a challenge.

The second key play occurred on the second drive by the Giants, where they had a third down and 11 on their own 20. Manning threw a 15 yard pass to Toomer that would have achieved the first down, but Toomer dropped the ball. The Giants' VF before the play was 17%, and after it was 16%. If the pass would have been complete, the Giants' VF would have risen to to 23%; therefore, this dropped pass cost the Giants 7% in VF.

On the subsequent Patriots drive, they faced a third down and 15 at their own 46. Brady was sacked for a loss of 8 yards back to their own 38. However, Corey Webster was flagged for an illegal contact penalty, which gave the Pats a first down at the Giants' 49 yard line. Before the play, the Pats had a VF of 81%; the sack would have decreased that to 78%. However, the penalty increased their VF to 85%, for a cost to the Giants of 7% in VF. The penalty itself is long forgotten; what is remembered is the Brady to Moss touchdown pass that occurred 6 plays later at the end of the drive. Because New England is expected to score a from second and goal inside the five, the touchdown only increased the VF by 1%. As we have written all year, the plays that seem insignificant are often more important than the plays everyone remembers.

In the second half, the Giants opened up a 12 point lead, and the Pats faced a third down and 8 from their own 29 yard line. By this time, the Pats' VF had dropped to a startling 22%. However, the Pats used a Brady to Watson 15 yard pass to increase their VF to 28%. This was a huge 3rd down conversion.

The next key play was a 5 yard illegal formation penalty against the Pats, when they had first down and goal at the 1 yard line. This penalty, which is uncharacteristic of the Patriots, cost them 4% in VF. Our previous columns have noted that the chance of (eventually) scoring a touchdown on first and goal at the 1 is around 90%, while first and goal from the 6 is around 65%.

The play of the game was the 65-yard Brady to Moss touchdown pass. It increased the Patriots' VF from 37% to 64%, a phenomenal 27% increase. This was a big swing because it was a long pass, it was third down, and the lead changed hands. (The subsequent two-point conversion added another 4% VF.) According to VF, this offensive play was the Patriots' most valuable of the entire season. It is quite poetic that the record setting touchdown pass was also the most meaningful play in a purely objective measure like VF.

The Patriots now have a perfect season. The odds of that are very long, which explains why it has only happened twice in 75 years. But what are the odds? If each game is even money, the odds of finishing 16-0 are less than 1 chance in 65 thousand. Of course, the Patriots were heavy favorites in most games, so their odds are better than that. Supposing a team is a 95% (19 to 1) favorite in each game, the likely of a perfect season is 44%. But if a team is only an 85% favorite for every game, 16-0 is 7% long shot. Using the GridIronMine.com opening VF for the Patriots (they were 94% or higher in 9 games and the lowest was 70%), the likelihood of the Patriots winning all 16 in retrospect is only 1 in 8. In other words, if the 2007 season were played 100 times, the Patriots would win all their games about 12 times.

Patriot plod past inept Jets

Posted by GridIronMine on December 16, 2007 | permalink | 0 comments

This article appears in the Patriots Football Weekly and PFW online. The VF percentages quoted in this article refer to the graph presented in the hardcopy of the PFW, which uses team-dependent VF. The online tools use the team-independent (or NFL average) VF.

(click to enlarge)

The Patriots started week 15 as a the largest favorite in the history of GridIronMine's Victory Forecast (VF) system. At the opening kick, the Pats had an almost certain 98% chance to win.

Because of the large initial advantage, there were really no key plays in the first half that caused any significant swings in VF. The most important play for the Jets was obviously the blocked punt returned for a touchdown. But that only resulted in a 3% VF increase for the Jets. While a small absolute increase, this represented a more than doubling of the Jets chance to win: from 2% to 5%.

The second half was also relatively event free, as each team scored only 3 points. There were two plays of note. The first was the Jets' decision to attempt a 33 yard field goal on 4th and 1, down 17-7. Considering the distance to make the first down and the time left in the game (6:18), the Jets should have gone for the first down. Interestingly, their VF did not increase at all upon making the field goal, despite narrowing the deficit to 7 points---again, this is because the GridIronMine VF system expects the Jets to go for the first down.

The other key play was the reversal of the touchdown catch by McCareins. This was clearly not a catch and was correctly reversed upon review. If this catch would have stood, the Jets would have increased their VF to 15%---not good, but much better than anyone thought possible before the game. However, the incompletion kept the Jets' VF at 7%. Subsequently on the drive, Nugent missed a field goal, which increased the Patriots' VF to 99%. Even if the field goal were made, the Patriots still would have a VF of 93%.

GridIronMine.com Nugget

In 2007, 43% of NFL games have been decided by seven or fewer points (47% by 8 or fewer). Many of these games come down to a single drive near the end of the game, where end-game coaching decisions are extremely important. This nugget, as well as future nuggets, will investigate proper use of timeouts. When a coach uses his timeouts in the right way, what would otherwise be a loss can turn into a win.

Before we go into details, we want to emphasize that determining the proper use of timeouts is not trivial. A head coach has many duties and doing addition and subtraction on the fly is something that GridIronMine.com believes should be the sole duty of a dedicated assistant coach.

In week 10, there were several high-profile misuses of timeouts. The one that generated the most attention was Tony Dungy's timeout in the Colts/Chargers game that was used to argue an illegal shift penalty right before Adam Vinatieri missed a chip-shot field goal. In fact, Dungy apologized, saying he should not have used the timeout to argue a call. While it is true that he shouldn't have called the timeout, it was not the only misuse of a timeout in that game. The rest of this nugget will focus on one situation---to show the complexity of calling timeouts in the proper manner.

The situation begins just a few plays before the missed field goal after the Colts completed a pass in bounds to Joseph Addai to the 15 yard line. There was 2:52 to go at the end of this play, with the Chargers leading 23-21, and the Chargers had two timeouts left. Norv Turner correctly determined that he needed to use timeouts on defense, anticipating that otherwise the Colts would run the clock out and win the game on a Vinatieri field goal. (While Vinatieri missed, a chip-shot field goal of that distance is made over 90% of the time, so Turner has to coach assuming Vinatieri is going to make the field goal.)

Turner called a timeout before the first down play, at 2:44 to go. On first down, the Colts ran the ball for 3 yards, in bounds. Turner then called the Chargers' last timeout at 2:36, after this play. On second down, the Colts ran the ball for 4 yards, in bounds, which took the clock down to the two-minute warning. On third down, they ran the ball for 2 yards, in bounds, which should have left the Chargers, after a made field goal, with about 1:05 to go (following the kickoff). If the Chargers had not used their timeouts, the Colts would have run their first down play before 2:12 (40 seconds from 2:52, when the previous play ended) and, assuming they run the ball in bounds, their second down play right after the two-minute warning. Basically, the Chargers used two timeouts to force the Colts to run one extra play before the two-minute warning. This is a very poor return on investment.

One clear mistake was that Turner waited eight seconds to call the first timeout. Had he called the timeout immediately (at 2:52 to go), it is possible that he would have forced the Colts to run three plays before the two minute warning, giving his team about 1:50 to score following the kickoff after the made field goal---an entire 45 additional seconds, which is an enormous difference. However, there is no guarantee because the first two plays might have taken the clock down to 2:00. Additionally, as we will explain in a future nugget, the defense never wants to allow the offense to run a play that will start before 2:00 to go and end after 2:00 to go.

The optimal way to use the timeouts instead would have been to wait until after the two minute warning to start calling them. Under this scenario, the Colts would have had to snap the first down play at 2:12 (again, 40 seconds from 2:52). Assuming the play ended in bounds, the two-minute warning would occur. Assuming then that the Colts ran two more in-bounds plays without getting the first down (which did in fact occur), the Chargers would have been able to call both timeouts, giving them approximately 1:40 to go following the kickoff after the made field goal---35 additional seconds.

Of course, this is just one situation. Next week we will give general rules of thumb for calling timeouts.

Powerline Blog

Posted by Vince on December 15, 2007 | permalink | 0 comments

Many thanks to Paul Mirengoff of Powerline Blog for mentioning this site.

I need to say that my analysis (comparing NL ERA vs. AL ERA) was a quick, back-of-the-envelope calculation. For example, I based it on runs scored, not earned runs. I am certain the that the DH has an upward effect on AL ERA, but I have less confidence in the range I gave Paul (+0.2-0.4).

Regarding Roger Clemens, I don't have any idea whether he used steroids. But neither does Mitchell, which is irresponsible.

BCS mess

Posted by Vince on December 11, 2007 | permalink | 0 comments

The big question once again is who should be in the BCS championship game. I fully admit that I don't know. The point of this post is that nobody can know. The data do not support any conclusion.

However, we do know that the voters (collectively) in the two human polls have no integrity because LSU hopped over VT even though both teams won conference championships. Moreover, VT beat a tougher opponent more convincingly. Clearly, there is a contradiction between the last two regular season polls: both cannot be true. This begs the question should we believe either poll? It is very hard to treat the human polls with much seriousness after this Kerry-like flip-flop.

What I would rather point out is that there is insufficient data to rank teams. There are 100+ Div 1A teams, each plays 12 opponents. Thus, there is no direct data linking a team with nearly 90% of the other teams. Moreover, this information is clustered because teams play in conferences making it even harder to compare teams in difference conferences. Finally, the better team does not always win a game. Therefore, you cannot rate teams merely by the outcome of a single game.

The table below shows the inter-conference games between the BCS teams. (Not including ND because there is no point in piling them on this year.) Each conferences record against another conference is shown in the corresponding row. For example, the 1-0 in the first row indicates that the ACC won the only game with the Big 10 (Duke over Northwestern).

	ACC	PAC	B10	B12	SEC	BEast	total
ACC	—	0-0	1-0	2-2	3-4	3-4	9-10
PAC	0-0	—	1-2	2-0	1-0	1-1	5-3
B10	0-1	2-1	—	0-2	0-0	3-0	5-4
B12	2-2	0-2	2-0	—	1-2	0-0	5-6
SEC	4-3	0-1	0-0	2-1	—	1-2	7-7
BEast	4-3	1-1	0-3	0-0	2-1	—	7-8

The point to take away from this table is that there are very few inter-conference games. For example, SEC didn't play the Big 10, the ACC didn't play the PAC 10, and the Big 12 didn't play the Big East. Only 3 out of 15 inter-conference match-ups had more than 3 games (interestingly, all involve the ACC). Simply put: there is insufficient inter-conference data to draw a definitive conclusion. The data is not statistically significant.

Let's look at one problem. LSU and VT had identical records (11-2; BCS conference champs) but LSU stomped VT in the second game of the season so it is reasonable to rate them higher than the VT. Except that 4 of 6 computer indexes rate VT higher. There must have been some other evidence suggesting VT is stronger than LSU. They did not play a common opponent, so we must assume that VT's wins are of higher overall quality. VT's wins are against ACC teams and weak non-BCS teams, therefore, the computers must have concluded that the ACC is a stronger conference than the SEC. One wonders if Clemson had not beaten South Carolina on a last second FG would the indexes have ranked LSU ahead of VT? On the other hand, I cannot explain why Sagarin ranks VT above LSU and ranks the SEC first and the ACC distant fifth.

A similar problem occurs when comparing Oklahoma and LSU. They didn't play each other and there were only 3 inter-conference games. Basically, those two teams are incomparable. Nevertheless, this is better than comparing Ohio State and LSU. No Big 10 team played an SEC team. The closest comparison we can find is OSU beat Kent State, which lost to Kentucky, which beat LSU. However, what to conclude from that is anyone's guess. There is a saying that no information is better than bad information. The BCS might benefit from considering this.

There is more to say, which will come in later posts.

Pittsburgh no match for New England

Posted by GridIronMine on December 11, 2007 | permalink | 0 comments

This article appears in the Patriots Football Weekly and PFW online. The VF percentages quoted in this article refer to the graph presented in the hardcopy of the PFW, which uses team-dependent VF. The online tools use the team-independent (or NFL average) VF.

(click to enlarge)

The Patriots started week 14, as a smaller favorite than usual. With the NFL's top-ranked defense coming to town on the heels of two close games, GridIronMine's Victory Forecast (VF) system at the opening kick showed the Pats as having a 74% chance of winning against the Steelers.

The Steelers stopped the Pats on a 3-and-out on the Pats' first possession. This year the Patriots start most games very fast and often put teams away in the first half, if not the first quarter. Through 13 games the Patriots have 7 touchdowns and 4 field goals on their opening drive. Pittsburgh joined the Colts as the only two teams to stop the Pats opening drive. In fact, Pittsburgh forced three 3-and-outs in the first half (one was a missed field goal) and another in the second half. This feat equals what Baltimore did the week before. Over the entire season, the Patriots have had only 11 first-half drives go 3-and-out, and 6 of those have come in the last two weeks.

On the other hand, the Steelers opening drive was in excess of 8 minutes that ended in a Jeff Reed field goal. It was on this drive that the Steelers achieved their maximum VF, 43%, which occurred when they got inside the Pats' 10. However, the Pats quickly regained their footing, increasing their VF to 80% and 85%, respectively, on two Brady-to-Moss touchdowns.

One key drive was Pittsburgh's last of the first half. This drive was impressive in many ways. First, the Steelers went for the first down on 4th and 1 on their own 49 and made it. This was clearly the right decision, given the short distance (it was much less than 1 yard) and the Patriots dominant offense (making a punt a bad play). Converting the first down increased the Steelers VF by 6%. Then, the Steelers lost yards on two penalties, the second of which came on an incomplete pass play. This set up either a 3rd and 15 (if the penalty is declined) or a 2nd and 25 (if it is accepted). Belichick accepted the penalty, which GridIronMine finds to be the correct choice (by 1% in VF). However, the Steelers gained 24 yards on the next two plays and then went for the first down again on 4th and 1 at the Patriots 40---again the right call, and it was converted, resulting in a 4% increase in VF.

However, Mike Tomlin got cold feet on the next 4th and short. After Roethlisberger threw incomplete on a miscommunication with Hines Ward, the Steelers had 4th and 2 with 2:36 left in the half. In general, this is a situation where teams should go for the first down; the point that is forgotten is that the chance of making the first down is not that much lower than the chance of making the field goal (about 65% for the field goal to 50% for making the first down, and if the distance is closer to one yard than two, they are approximately even). Moreover, with 2:36 left, it's especially good to go for the first down, because if it is converted, the Pats will almost surely not get the ball back the rest of the half. This is significant: kicking a field goal means that the best case for the Steelers is gaining 3 points. In the worst case the Steelers lose 4 points--- if the Pats score a quick touchdown. With the Patriots potent offense, they are highly likely to get into field goal range (which they did), and at the half, the Steelers ended up right where they were before the field goal attempt. As we have pointed out in prior columns. teams should more often try to win with their offense.

The second half was not too interesting from a VF perspective: the Pats started with an 80% VF, which went to 89% and then 95% after the flea-flicker touchdown from Brady to Gaffney and the Brady to Welker touchdown, respectively. After that the Steelers embarked on a drive from their own 43 to the Pats' 1 yard line, which ended when the Pats stuffed Ward on a 4th and 1 end-around. This drive was noteworthy only in that it barely increased the Steelers' VF (at any point during the drive). The Steelers started at 4% and never got above 6%. This is because of the large lead and lateness in the game---even with a touchdown, Pittsburgh would have been down two scores.

Ravens allow Pats to escape

Posted by GridIronMine on December 5, 2007 | permalink | 0 comments

This article appears in the Patriots Football Weekly and PFW online. The VF percentages quoted in this article refer to the graph presented in the hardcopy of the PFW, which uses team-dependent VF. The online tools use the team-independent (or NFL average) VF.

(click to enlarge)

The Patriots started week 13, as usual, as a heavy favorite over the Ravens. GridIronMine's Victory Forecast (VF) system at the opening kick showed the Pats as having a 94% chance of winning. Surprisingly, after being severely tested last week against the Eagles, the Patriots were taken to the wire again. GridIronMine.com certainly did not expect the Ravens to play as well as they did.

Because the Pats were overwhelming favorites at the beginning of the game, the Ravens spent the first half primarily keeping the Pats' VF away from 99%---which most teams struggle to do given the fact that the Patriots are usually heavy favorites.

Just before the half, a key play was the Ed Reed interception of a Brady pass and subsequent 33 yard return and fumble. Had Reed not fumbled, this play would have given the Ravens an 8% increase in VF. The fumble itself gave the Pats an 8% increase in VF. In other words, the play broke even in VF---even though the Pats lost 8 yards on the play, they retained first down and the half was close enough that VF assumed the Pats would simply run out the clock---which they subsequently did.

After kicking off to start the second half, the Pats' VF stood at 82%. We note that while the score was tied half, just as the score is of course tied at the opening kickoff, the Pats' VF is lower at the start of the second half because the game is half over and the Pats have not taken care of business.

The Ravens scored on their next possession to move ahead 17-10, and the Pats immediately answered with a touchdown of their own. The first interesting play on this drive was a 3rd and 2, where the Pats only got one yard, and lost 7% in VF (because they didn't get the first down). This was followed by the Patriots converting on 4th down, which gave them back the 7% in VF that they lost on the previous play.

After the Ravens scored on the next drive to go up 24-17, the the teams traded possessions, with the Ravens' ending on an interception by Sanders plus a 42 yard return, for a 12% increase in VF. The Pats got an additional 12% on the short pass to Maroney that he ran for 43 yards, on a drive that ended with a field goal by Gostkowski.

The teams traded the ball without scoring, and the Pats finally took over the ball at their own 27 with 3:30 to go, and only a 30% VF. They would need a touchdown to win, and a touchdown they got. However, it was not without several key interesting plays (and a bit of good fortune). The Pats had a 4th and 1 play from the Ravens' 30 yard line. First, the Ravens called a timeout on a play where they actually had a Brady sneak stopped. Then, the Pats appeared to be stopped again, except there was a dead ball false start penalty on Hochstein. This penalty cost the Pats 10% VF (because 4th and 6 is so much more difficult to convert than 4th and 1). However, it appeared that the Ravens had the play stopped; if it had counted, the Pats' VF would have dropped to 7%.

On the 4th and 6, Brady converted on a run plus a 5 yard penalty, which gave the Pats the ball on the Ravens' 18 with 1:38 to go. This increased the Pats' VF by a whopping 44% to 62%. At this point, GridIronMine.com expects the Pats to win---plenty of time is left, they are only down by 4, and have a first down. However, following an incomplete on 3rd down, NE's VF slipped to 38%. The incomplete pass on 4th down dropped it down to 1% because the Ravens (would have) had the ball with less than one minute remaining; they could have just taken a knee to win. But a holding penalty on Winborne gave the Pats new life and a huge VF increase of 72%. Wild swings in VF such as these are commonplace in a close game that comes down to the last drive. After the Brady to Gaffney TD, the Pats' VF stood at 85%, because the Ravens still had one last chance, which ended on a Hail Mary pass that was stopped at the three yard line.

Patriots survive Eagles

Posted by GridIronMine on November 28, 2007 | permalink | 0 comments

This article appears in the Patriots Football Weekly and PFW online. The VF percentages quoted in this article refer to the graph presented in the hardcopy of the PFW, which uses team-dependent VF. The online tools use the team-independent (or NFL average) VF.

(click to enlarge)

The Patriots started week 12 as usual, as a heavy favorite over the Eagles. GridIronMine's Victory Forecast (VF) system at the opening kick showed the Pats as having a 94% chance of winning.

This game might rank as the most surprising game of the entire NFL season. With Donovan McNabb out, no one (including GridIronMine.com) gave the Eagles much of chance to come close to a victory.

Because the Pats were overwhelming favorites at the beginning of the game, the Eagles spent the first half primarily keeping the Pats' VF away from 99%---a feat in itself. After Samuel's interception return put the Pats' VF at 98%, Westbrook's touchdown run cut it back to 92%. Similarly, Evans' touchdown run put the Pats' VF at 95%, but a Feeley to Lewis touchdown pass cut it to 89%. Finally, after a Pats field goal, the teams traded touchdowns once more, leaving the Pats with a VF of 85% right before the half.

One interesting play in the first half occurred when the Eagles also got a 4% increase in VF on their successful onside kick after Lewis' score. GridIronMine.com wonders why more teams do not try this against the Patriots---when a team scores on virtually every drive, why not risk giving them the ball at the 45 in exchange for the chance of taking over possession yourself?

After receiving the second half kickoff, the Pats' VF stood at 87%. We note that while the Pats had a larger lead at the half than they did at the beginning of the game, their VF is lower because the effect of the Pats being the favorite to win the game is lessened---half the game is over and the Pats haven't taken care of business.

The next key play was the offensive interference call on Randy Moss that nullified a touchdown.
The penalty itself decreased the Pats' VF by 2%. Then, this penalty led to a failed third down conversion and a missed field goal by Gostkowski, which additionally decreased the Pats' VF by 3 and 5%, respectively. Overall, this sequence cost the Pats 11% in VF.

The Eagles then took the ball after the missed field goal and marched down the field and scored a touchdown. This drive was noteworthy because of the touchdown play. It came on a Feeley to Brown pass on 3rd and 4 at the 8 yard line and resulted in a 13% increase in VF for the Eagles. Generally speaking, an 8-yard touchdown pass is not that large of a swing in VF, but in GridIronMine's system, a swing from a three point deficit to a four point lead is one of the largest swings that can occur on an offensive touchdown.

The next key play was an offsides penalty on Trent Cole on 4th and 3 when the Pats were punting. This penalty is considered by GridIronMine.com to be unforgivable---the Pats have the best offense in the league, and blocking a punt occurs at most a few times per year per team, so presumably the Eagles' special teams coach instructed his players to make sure they did not jump offsides. This play resulted in an 8% VF increase for the Patriots, as the Patriots not only retained possession, but had the ball in good field position at their own 45. The drive ended in failed 3rd and 4th down plays that decreased the Pats' VF by 8 and 10%, respectively, but this does not mitigate the incredibly poor judgment of jumping offsides.

Finally, the Pats converted the key 3rd down of the game. With 2:27 to go, they were faced with a 3rd and 1, where a first down virtually ices the game. Matt Light committed a false start, costing the Pats 8% in VF (because 3rd and 6 is so much harder to convert than 3rd and 1), but Brady calmly threw to Gaffney to convert the 3rd and 6. This play made it such that the Eagles would get the ball back with no time outs and less than 30 seconds left at around their own 20---which is almost certain victory for the Patriots---so accordingly increased the Pats VF from 79% to a near-certain 98%.

Bills fold

Posted by GridIronMine on November 20, 2007 | permalink | 0 comments

This article appears in the Patriots Football Weekly and PFW online. The VF percentages quoted in this article refer to the graph presented in the hardcopy of the PFW, which uses team-dependent VF. The online tools use the team-independent (or NFL average) VF.

(click to enlarge)

The Patriots started week 11 as a heavy favorite over the Bills; similar to most weeks, the Pats had a 94% chance of winning at the opening kick, according to GridIronMine's Victory Forecast (VF) system. It did not take long for the Patriots to get to 99%. They broke their own record (set previously in the Dolphins game in week 7) by getting to 99% before 7 minutes were gone in the first quarter. In fact, they had a VF of 98% after less than 5 minutes.

The Patriots' VF suffered a brief drop to 96% after a Losman to Parrish 43 yard touchdown pass, but went back up to 99% shortly thereafter with a Moss touchdown that made it 21-7. Their VF did not drop below 98% again.

At this point, we again look at the chance for the Patriots to go undefeated. They are 10-0 and have six games left, playing home games against the Eagles, Steelers, Jets, and Dolphins, along with road games at the Ravens and Giants. The Pats will likely be a 98% or better shot to win the three home games aside from the Steelers, a 90% shot to beat the Steelers, and at least 90% to win the the two road games. Putting this all together, conservatively, the Pats have a 70% chance to go undefeated. Of course, all of this assumes that Bill Belichick does not rest starters after they have clinched home field advantage.

GridIronMine.com Nugget: A punt is a turnover

Obviously, a turnover is undesirable. However, a punt, which also ends a drive, is also a negative, although many fans and coaches do not consider it as such. This nugget looks at the difference between a drive that ends in a turnover outside of scoring position to one that ends in a punt. Keep in mind that in 2006, 43% of all drives ended in a punt and 15% ended in a turnover (with interceptions accounting for 60% of all turnovers).

One cost of a turnover is the difference in the line of scrimmage where the opponent starts its drive; if a punt is returned to the original line of scrimmage it is effectively the same as an incomplete 4th-down pass. Thus the only objective difference between a punt and a 4th-down turnover is the difference in the opponent's starting field position. An average punts nets about 35 yards of field position. Not considering end-game situations, 10 yards of field position changes Victory Forecast (VF) by approximately 2% when the lead is one score or less. In other words, a failed 4th-down conversion or a turnover on 4th down is about 7% worse than an average punt.

While that is a significant reduction in VF, it is not uncommon. For example, it is comparable to a 5-yard penalty on 1st & goal from the 1. In other words, a failed 4th-down conversion is a significant negative, but not typically a game-breaking play. This is one of many reasons GridIronMine.com often recommends trying to extend a drive on 4th and short.

The second cost of a turnover is the ending of the drive. When a drive is on life-support (4th down or 3rd and long), the end of the drive is nearly certain. Thus there is very little opportunity cost for ending the drive on a turnover, because it was probably going to end anyways on a punt or on downs. In this case, the cost of a turnover is primarily the difference in field position. For example, if the other team takes over at the same line of scrimmage, there is no objective difference between an interception on 4th down and a punt. That is why it is often better to bat down a 4th-down pass than to try to intercept it. Similarly, on 3rd and long there is no objective difference between an interception that puts the line of scrimmage 35 yards down field and an incomplete pass followed by a 35-yard net punt. Therefore, one can justify forcing a downfield throw into coverage on 3rd and long---especially if the receiver is likely to win a jump ball (which is the case with, say, Randy Moss). The average downfield interception (more than 25 yards) moves the line of scrimmage about 20 yards down the field, so a typical 3rd down interception of such a downfield pass is only 3% worse than the typical punt.

When a drive is likely to end in a punt, the cost of a turnover is the difference in field position. However, when a drive still has some promise (likely first down conversion or in field goal range), a turnover has a much larger cost, but that is another discussion.