Will Adrian Peterson leave Minnesota for a warmer climate in 2015?
26 Jun 2006
Guest column by Jason McKinley
Competitive balance defines the NFL. Most games are still in doubt in the fourth quarter. Since 1996, 1,474 out of 2,598 regular season and postseason games have featured a team trailing by eight points or less in possession of the ball in the fourth quarter. In 603 of those 1,474 games, the trailing team won. Therefore, nearly a quarter of all victories in the last decade have been the result of late and dramatic rallies.
Quarterbacks are associated most strongly with comebacks. How many times was it said that John Elway "willed his team to victory" following a come-from-behind rally? Johnny Unitas is often credited with the creation of the two-minute offense. In his Hall of Fame career, Joe Montana overcame multiple fourth quarter deficits. In fact, Joe Montana overcame multiple fourth quarter deficits in the postseason alone. Hell, Joe Montana overcame multiple fourth-quarter deficits in the postseason even if you only count his two seasons with the Chiefs. Today, quarterbacks like Tom Brady and Brett Favre are discussed in heroic terms mainly because they're able to pull out victories in situations where mere mortals would surely fail.
Obviously, many comeback attempts prove futile. While 603 games since 1996 have featured come-from-behind wins, another 1,322 games have ended with the close trailer still behind when the final gun sounded. Any instance in which a team had possession of the ball at some point in the fourth quarter and was trailing by eight points or less was considered for the study. This naturally would include any successful comeback regardless of the largest deficit faced â€“ one can't complete a twenty-point comeback without getting the score under 9 points at some time. It also gives a reasonable cut-off for failed comebacks: where one drive could potentially change the lead or send the game to overtime. On occasion a team will get the ball very early in the fourth quarter, then again later, and (very rarely) a third or fourth time, and be within one score every time. In this study, that is counted as only one failed game opportunity.
While quarterbacks get accolades for the comebacks, head coaches often get blamed for failures. Why do we think of Tom Brady, and John Elway as responsible for leading come-from-behind victories, but not Bill Belichick, Mike Shanahan, and Dan Reeves? Is a quarterback more responsible for a comeback, or is it the head coach? Is a head coach more responsible for holding a small lead, or is it the quarterback?
We can start to figure this out by looking at the individual performance of quarterbacks in comeback situations. Over the past decade, no quarterback has had more fourth-quarter comebacks than Drew Bledsoe. Then again, no quarterback has had more fourth-quarter comeback opportunities than Bledsoe. Are Bledsoe's 19 wins in 61 comeback chances more impressive than Donovan McNabb's 12 in 27? A raw total says that Bledsoe is better, and a straight winning percentage says that McNabb is better. Neither seems like an ideal ranking tool.
A simple comparative ranking system can be formulated with the help of a statistical method known as a "t-test." A t-test is generally used to test a statistical hypothesis against some population parameter. The result is given as a "p value," where a lower p value indicates a more significant result. A t-test will usually reward a good average over a large number of trials more than a great average over a small number of trials, which is necessary in this study due to the wildly different and often very small sample sizes for each quarterback. A Shapiro-Wilk test was executed and it was determined that the population had an approximately normal distribution, which is necessary for this type of testing. Here the t-test is used to determine the significance of a quarterback's actual number of comebacks compared to the expected number given his opportunities.
(A word of caution is in order: Please do not use t-tests the way they are used in this article. For our purposes, the significance levels were actually used to rank order every quarterback that has been in a comeback situation since 1996. This is not in the spirit of what a t-test is supposed to do. However, saying someone is in a group that is significantly better than average, worse than average, or not significant versus the sample population at some p value is not nearly as fun as saying "This guy ranks 8th and this guy only ranks 37th!" Anyway, if you are a professional statistician, do not attempt this at work!)
With a test in place for ranking performance, we can then implement another test, an analysis of variance, to help determine responsibility for comebacks and holding leads. An analysis of variance can break down the components of variation between and within groups and help determine which factors (if any) are important. In this study all possible two-way combinations of quarterbacks and coaches were examined. All quarterbacks who have been in a comeback or lead-holding situation under more than one head coach comprised one group. All coaches that have had multiple quarterbacks in comeback or lead-holding situations comprised the other group. Analyses of variance were run on each group, examining comeback ability and the ability to maintain leads, using modified t-test results as the dependent variables.
The general picture from these analyses of variance is that quarterbacks are more important than coaches in coming from behind to win, and coaches are more important than quarterbacks in holding leads. For example, the results indicate that Tom Brady should maintain a similar ability to bring his team from behind to win regardless of whether or not his coach is Bill Belichick. Furthermore, Bill Belichick should maintain a similar ability to hold on to a one-score, fourth-quarter lead whether or not his quarterback is Tom Brady.
These results make intuitive sense. A team that is trailing needs to be able to move the ball and score. Calling the right plays in this situation is certainly important, but execution by the quarterback and his surrounding cast is paramount. Meanwhile, a team that leads by a small margin will require a defensive stop, followed by utilization of a clock-killing offensive strategy usually predicated on the running game. This largely negates the quarterback's role.
We looked at every game from the past ten seasons to see which recent quarterbacks have been the best at rallying their teams back from a deficit. And although he was known for comebacks early in his career, the top comeback quarterback might surprise you: it's Jake Plummer, slightly ahead of Peyton Manning and Vinny Testaverde. It's a surprising conclusion, but that's the kind of insight rational statistical analysis can provide.
|Table 1. Top 10 quarterbacks at comebacks since 1996|
Plummer's comeback ability has drifted towards average since his first few seasons but his overall numbers still rate the best. Under Vince Tobin, he was a stellar 10-11 when trailing by one score in the fourth, and since then he is a solid 9-17. Peyton Manning holds the single-season mark with six comeback wins in 1999. Only the coldest, hardest, football fact-seeking Patriots fans would express surprise at Peyton Manning's high rank, but Vinny Testaverde is a bit of an eye-opener. However, Vinny was a comeback machine in 2000 and 2001, racking up nine wins in 17 comeback chances during those two seasons with the Jets. No other quarterback in the last decade had more than eight comeback wins in any two-year span.
Tom Brady is next on the list and, remember, these numbers do include the postseason. Brady is one of only a handful of quarterbacks with a winning record in more than three games with a fourth-quarter deficit. The others are Marc Bulger (10-5), Ben Roethlisberger (7-2), Steve Young (7-4) and John Elway (7-6). Bulger, who ranks eighth by this metric, is the only one in that group that has yet to win a Super Bowl.
(Elway holds the NFL record for fourth-quarter comebacks with 47, but this study only includes the final three years of his career.)
Donovan McNabb managed to crack the top 10 despite the handicap of not having Terrell Owens on his team for most of his career. When trailing by a close score in the fourth-quarter, McNabb's record is 10-12 without Owens and 2-3 with him. McNabb is one of three NFC Champion quarterbacks in the top 10, along with Jake Delhomme and Kerry Collins. Delhomme has had at least one successful comeback in every year he's had an opportunity. That includes his one chance playing for Mike Ditka's Saints at the end of the 1999 season. Another of Ditka's short-term quarterbacks with the Saints, Kerry Collins, actually did most of his comeback damage between 2000 and 2002 with the Giants. He had 11 comebacks in 23 opportunities in those three seasons, which is the highest number of comebacks for any quarterback over a three-year span.
The interesting cases of Jon Kitna and Jay Fiedler complete the top 10. Neither has ever been considered a franchise quarterback. Neither has a rifle arm. Neither was drafted coming out of college and both had to cut their teeth in NFL Europe before getting a chance in the NFL. Yet based upon their performance, it can certainly be argued that they deserved every one of the 139 NFL starts that they've racked up. In the last decade, Kitna and Fiedler combined for 25 comeback wins in 60 opportunities. This is six more come from behind victories than Drew Bledsoe, with one less opportunity. That is not meant as a condemnation of Bledsoe, who has been very average in this situation.
Among the 10 quarterbacks with the worst comeback records over the past 10 years, four have been to the Pro Bowl (Table 2). But most have spent more time holding a clipboard and signaling in plays than actually starting. Six have started a playoff game and three even have Super Bowl rings (OK, Banks and Griese were backups in their Super Bowls). Their career quarterback ratings range from 63.2 to 94.1. They came from all over the draft: two first-rounders including a number one overall selection, one each from the second, third, fifth and seventh rounds, two fourth-rounders, and two undrafted free agents. Despite these differences in background and performance, they have at least one thing in common: Each has lost at least one starting job during his career.
|Table 2. Bottom 10 quarterbacks at comebacks since 1996|
Sometimes they lost the job because of injuries, other times because of poor performances. In other cases the starting job was clearly temporary, until their team's hot, new, highly-drafted prospect was proclaimed ready. And in Jeff George's case with the Falcons, a nationally televised, profanity-laced sideline tantrum directed at the head coach signaled the end.
The poor showing by these players doesn't mean they don't have the overall ability to play quarterback at a high level. It is, however, an indictment of their ability to consistently bring their teams from behind. Mark Brunell is a fine quarterback despite his 14-39 record since 1996 when trailing by one score in the fourth quarter. Brunell has enjoyed a positive DVOA in five of his last six seasons. Since 1996, his teams' combined record when he starts is 76-64. But when he's down in the fourth quarter, he stays down.
One of the more surprising names on the "worst" list is Kurt Warner. He started two Super Bowls and won one. In each of those years he was the league MVP. Yet that obviously had more to do with gaining early leads than it had to do with coming back. One of his five career comebacks came in the 1999 NFC Championship game against the Buccaneers. His touchdown pass to Ricky Proehl with 4:44 left gave the Rams an 11-6 victory and a trip to the Super Bowl. It was a great time for the first comeback win of Warner's career, but he would go on to have only four more in more than 20 opportunities through 2005.
As Warner's case shows, a team does not necessarily need a quarterback with gaudy comeback ability to make a Super Bowl. There are six quarterbacks who began their careers after 1995 that have made the Super Bowl. Brady, McNabb, Delhomme and Warner have been discussed as members of the top 10 and bottom 10. The other two are Ben Roethlisberger and Matt Hasselbeck. Big Ben ranks 16th out of 162, but Hasselbeck ranks 149th. Hasselbeck has the same comeback record (5-16) as David Carr. Roethlisberger's record is comparable to Bulger's: he also began his career with a 7-2 record in comeback situations. In addition, Brady is 7-2 in his most recent comeback chances.
Brett Favre is often cited as a master of the comeback. He has been above average over the last decade, but not by much. His 16-34 record is approximately one win better than would be expected â€“ reasonably good, but not great.
Another surprise is the rating for Doug Flutie. Some call Flutie's comeback ability "Flutie Magic." Mozart called it "Die Zauberflutie." (Flutie has been around a long time.) The idea is that if Flutie is in the game, his team always has a good chance to come from behind and win. But that's not true -- in fact, he's actually below average. Six come-from-behind wins in 23 opportunities ranks Flutie 146th out of 162 eligible candidates.
It is probably not appropriate to judge Hall of Fame inductees by their rankings on this list, because of its limited time constraint. There are six Hall of Famers on our list, but all played most of their careers prior to 1996. Steve Young and John Elway still grade out very well, and Dan Marino and Jim Kelly are above average. Troy Aikman and Warren Moon had records of 6-16 and 4-12 when presented with a comeback opportunity after 1995. Those match the records of Joey Harrington and Scott Mitchell, respectively, and rank them in the bottom quartile. It's unclear from this study if this is a true indication of their total career performances. However, based on the analysis of variance results discussed earlier, it may be more reasonable to assume that this is somewhat representative of their total careers than to assume that it is not.
Turning our attention to head coaches, seven of the last 10 Super Bowls have been won by coaches who rank among the 10 best at holding a one-score, fourth-quarter lead (Table 3). Nine of the top 10 have either been to a Super Bowl or coached in multiple championship games, with the exception being Jim Haslett. Of course, Haslett spent his entire head coaching career with the Saints; he's good, but he's not a miracle worker. Interestingly, three of these coaches have been relegated to subordinate jobs: joining Haslett are Jim Fassel and media whipping boy Mike Martz. Readers of Pro Football Prospectus 2005 will not be surprised to see Martz ranked so highly, although Bob Ryan and Michael Wilbon may feel that his inclusion in the top five invalidates the entire study.
|Table 3. Top 10 coaches at holding a lead since 1996|
The worst coaches at holding a one-score, fourth-quarter lead include Marty Schottenheimer and Mike Holmgren (Table 4). Both coaches are long-tenured and boast career records that are more than 50 games over .500. Holmgren has won a Super Bowl and coached in two others. Schottenheimer's postseason record is horrific, but his teams generally perform very well in the regular season. (He's the Flip Saunders of football!) Yet they both consistently field teams that get beaten in the fourth quarter more often than they should. George Seifert's appearance in the bottom 10 might come as a surprise as well. This study includes his time with Carolina, and just one of his glory years with the 49ers.
|Table 4. Bottom 10 coaches at holding a lead since 1996|
|70||Jim Mora, Sr.||19||12|
The Chiefs, in their coaching transition, have made a nearly-perfect swap according to this metric. Since returning to the NFL in 1997, Dick Vermeil has been almost perfectly average when it comes to keeping a small, late lead. Only one coach has him beat when it comes to mediocrity: Herman Edwards. That's right; the second most average coach by this metric is being replaced by the most average coach. Obviously, the Chiefs really did their homework in finding the best possible replacement for Vermeil.
Of course, not all comebacks are created equal. In the average come-from-behind, fourth quarter victory, a winning quarterback first gets the ball down by of 5.5 points with 11:47 to play. Meanwhile, in the average failed comeback, a losing quarterback first gets the ball down by an average of 4.6 points with about 8:10 to play. Those parameters were determined by looking at the point of the game where a team is down by the most points in the quarter with the most time remaining in instances of successful comebacks (whether or not the first drive yields any points), and by looking at the point of the game where a team is down by the least amount of points with the most time remaining when they get the ball in the case of a failed comeback. The drive with the smallest deficit faced (or in the case of multiple drives with the same deficit, the largest time remaining) was recorded.
Under these guidelines the vast majority of quarterbacks' comebacks and failed comebacks begin when they are down by between three and eight points (i.e., more than a field goal and less than a touchdown). But a few quarterbacks have had easier or harder comebacks and failed attempts.
|Table 5. Smallest average deficits overcome, minimum 2 games, 1996-present|
Seven quarterbacks have more than one successful comeback win with an average score to overcome of less than three points (Table 5). Yes, that's Ryan Leaf atop the list; he actually had two comeback wins in his NFL career. Eight quarterbacks with multiple career comeback wins have needed two scores on average to finish the deal (Table 6). Troy Aikman and Tony Banks didn't bring their teams from behind quite as often as the league average indicates they should have. But when they did, the degree of difficulty was "ALCOA Fantastic Finishes" impressive. "Time Remaining" in the tables represents the time left in the game when the quarterback got the ball for a drive that would be his first in the fourth quarter, regardless of whether or not that drive resulted in points, or whether or not the drive began in the fourth quarter.
|Table 6. Largest average deficits overcome, minimum 2 games, 1996-present|
Looking at the comebacks that did not materialize, six quarterbacks with more than one failed opportunity have an average points needed of less than three (Table 7). Ryan Leaf certainly had a lot of close calls in his career.
|Table 7. Smallest average deficit not overcome, minimum 2 games, 1996-present|
A complicating factor in this study has to do with a "near" comeback. For our purposes, a comeback was only counted as successful if it concluded with a victory (half-victories and half-losses were assigned to ties). What about a situation in which a quarterback brings his team from behind to take a lead only to see the other team march down and retake the lead with no time left? What about a quarterback putting his team in a position to win the game with a last minute field goal only to watch as the kicker shanks it? Including situations such as these would require a William Krasker-esque mathematical model which would assign appropriate win probabilities to different game circumstances. Such a model would be a wonderful achievement, but would be far too labor intensive in its creation to justify in this project.
The numbers tell a useful story as they are currently presented. For example, if every quarterback that is significantly "bad" at p < .001 (the bottom eight on the list) were given an extra comeback win, just for being nice guys, they would all still all be significantly bad at p < .05. Some would still be significantly bad at p < .05 if given two or three extra wins, and that is without adjusting for a new league where comebacks are decidedly more rampant because we're suddenly giving away wins or partial wins just for being close.
Football is a team game, and usually the culpability in a failed comeback lies with other players in addition to the quarterback. Quarterbacks receive a higher share of the glory regarding comebacks, but this is tempered by those times when they receive a higher share of the blame for losses. Jeff George was only 2-14 in games in which he had a chance in the fourth to bring his team back and win. But would anyone ever say, "Jeff George would have been great at bringing his teams back to win -- if his teammates hadn't constantly failed him"? Well, okay, would anyone besides Jeff George ever say that?
(Ed. Note: Jason Whitlock.)
Some quarterbacks have proven better than others in the art of the comeback. Some coaches have proven better than others at holding a small, late lead. These differences appear to be meaningful. Old coaches in new places like Dick Jauron and Herman Edwards should continue their career trends in terms of holding fourth-quarter leads, while quarterbacks with new teams like Daunte Culpepper and Aaron Brooks should retain similar abilities to bring their teams back and win.
So on October 22, if Mark Brunell gets the ball in the fourth quarter trailing by eight points or less to Tony Dungy's Colts, don't be surprised if the Redskins end up losing. And on November 19, if Jake Plummer gets the ball in the fourth quarter trailing by eight points or less to Marty Schottenheimer's Chargers, don't be surprised if the Broncos end up winning.
162 quarterbacks have had at least one fourth-quarter comeback opportunity since 1996. There are 24 instances in which two quarterbacks saw action in a failed comeback game, usually due to injury or ineffectiveness of the primary quarterback.
Based on t-tests, 21 quarterbacks have been significantly "good" at fourth-quarter comebacks since 1996 and 18 quarterbacks have been significantly "not good" by the same test (all at the .95 level). The top 10 and bottom 10 are listed above in Table 1 and Table 2. Here are the others:
Significantly good: Aaron Brooks, Tim Couch, Trent Green, Kent Graham, Steve Young, Ben Roethlisberger, John Elway, Kordell Stewart, Daunte Culpepper, Elvis Grbac, Rich Gannon.
Significantly bad: Neil O'Donnell, Doug Flutie, Frank Reich (yes, the same Frank Reich who led the greatest postseason comeback in NFL history in 1992, prior to this study), Gus Frerotte, David Carr, Jim Harbaugh, Matt Hasselbeck, Billy Joe Tolliver.
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