Math Says If Wes Welker Catches That Ball, The Patriots Win

Illustration for article titled Math Says If Wes Welker Catches That Ball, The Patriots Win

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We're all taught from a young age not to play the "if only" game—if I had only made that catch/hit that basket/tagged that runner… It's not a healthy exercise for young athletes, and can be an even worse one for professional competitors. "You win as a team and you lose as a team, and certainly one play wasn't why we lost," said Tom Brady, responding in his postgame press conference to questions about what many fans viewed as the costliest play of the game for the Patriots—the incomplete pass to Wes Welker late in the fourth quarter.

If I were Brady, then I would not be repeating his wife's line about the consequences of dropped passes either. But for a non-participant, a little dabbling in the dark art of if only doesn't hurt, especially if you're not a Patriots fan. So l decided to take a look at a few of Sunday's biggest plays to see just how big an impact they would have made if they had gone the other way. Because the "if only" game is only fun when it's played from the perspective of the losing side, I focused on the plays that broke the Giants' way. It turns out that just five plays accounted for most of the difference in the game.

First, the turnovers: The Giants fumbled twice Sunday night, but were lucky to escape unscathed on both occasions. The first fumble was on a third-and-3 from the New England 11 near the end of the first quarter. Although it was recovered by the Patriots' Brandon Spikes, he had eleven other teammates on the field with him when the play started. The penalty was a costly one. Had the fumble recovery held up and the penalty not taken place, the Giants would have gone from a 0.75 Win Probability (a 75 percent chance of winning the game) to a 0.60 WP, a drop of 0.15.


The game's second fumble just bounced the Giants' way. In the third quarter, Hakeem Nicks lost the ball after a hit by Jerod Mayo at the New England 30 and fullback Henry Hynoski recovered. Had the Patriots been able to get there first, the Giants WP would have been 0.26 instead of 0.40, a difference of 0.14.

On the following possession, Tom Brady evaded a sack and

under-threw a deep ball intended for Rob Gronkowski. Chase Blackburn was able to reel in the pick. Had the ball fallen incomplete or Brady not forced a deep throw while still under pressure from Jason Pierre-Paul, the Patriots would still have had a second-and-10 from their own 43, worth a 0.67 WP. But as it happened, the Giants had possession at their own 8, leaving the Patriots with 0.60 WP, a relatively small drop of 0.07. The difference is slight because the pass was so deep—the pick could be considered roughly the equivalent of an unsuccessful series followed by a very good punt.


That wasn't Brady's only big mistake, though. One of the oddest plays of the game was his first pass attempt, an intentional grounding that put the Patriots in a two-point hole and handed the ball back to the Giants at the very start of the contest. Deep passes down the middle of the field are rarely called for grounding and Brady seemed to pin this one on the refs: "It's a referee's judgment call. I was looking down the middle of the field and Tuck was coming to get me and I tried to get rid of it. The refs made the call." In this case, it was the right call. But on many occasions referees will give the passer the benefit of the doubt that a receiver made a bad read, and the decision could have really gone either way. As it was, the Patriots dropped from a 0.47 WP to a 0.40 WP on their very first offensive play of the game.

As the clock's final minutes count down in a close game, the leverage of every play ratchets higher. Ultimately, the Brady-to-Welker incomplete pass will be remembered as the biggest missed opportunity of the game, and rightfully so. With a 2-point lead and 4:06 left to play, Brady threw slightly high and behind Welker, who was able to get his hands on the ball but couldn't pull it in. Welker was near the New York 20, so had he and Brady made the connection, the Patriots would have been close to putting the game away. A complete pass would have meant a 0.95 WP, but after the ball dropped to the turf it was actually 0.65, a drop of 0.30.


Any of these five plays could easily have gone the other way. In total they represent 0.73 WP—nearly the entire difference between winning and losing. Win probability is obviously an abstract concept, but it helps put a concrete number on what we already intuitively understand. Numbers like this underscore how razor-thin the difference between winning and losing is, especially when the two opponents are evenly matched. This year's Super Bowl was like most other NFL games—it hinged on a handful of critical and unusual events. The conference championship games were no different: The Giants won thanks to two bungled punt returns by the 49ers, and the Patriots won in large part thanks to a missed 32-yard field goal attempt by the Ravens.

If the Patriots and Giants played a best-of-seven series like we see in pro baseball and basketball, no one would be surprised to see it go to seven games. We only get to see game one of a hypothetical series, and the Giants happened to get the breaks and make the plays.


Brian Burke is a former Navy fighter pilot and the founder of the website Advanced NFL Stats. He is a regular contributor at the New York Times's Fifth Down and the Washington Post's The Insider.