This week, we turn our attention to stats that measure the odds that a team will win a given game.
Win Probability and its player-driven cousin Win Probability Added (WPA) are stats advanced by Brian Burke of Advanced NFL Stats. Win Probability calculates the likelihood that a team will win the game before each and every play. WPA adds up the impact that an individual player has on those odds.
For instance, a team with a 40-point lead with 45 seconds to play has a Win Probability of 100 percent. Win Probability is a stat that explains what happened after the fact. Swings in Win Probability illustrate which plays had the most impact on a game.
These plays can be charted to produce a graphical representation of the swings of NFL games. For games with twists and turns, these charts can be dynamic.
With 7:08 to play, Drew Brees threw a touchdown pass to give the Saints a 22-10 lead. At that point, their Win Probability was at 94 percent.
All the Saints had to do was get a stop and run out the clock. That stop proved much harder to get than they expected, however. Jake Locker threw a 40-yard touchdown to Nate Washington just over a minute later, and the Titans were back in the game. Despite trailing by just five, however, they still only had a 17 percent chance to win the game. Even when a game feels close, one team can still have a major advantage.
In this case, the Saints had the ball and the lead with just six minutes to play. In many instances, the trailing team might never see the ball again. The Titans held the Saints to a three and out, and after the punt, they had a 26 percent chance to pull off the comeback.
Things didn't go well for the Titans. Despite moving into Saints territory, they failed on both third and fourth-and-short, leaving the Saints with ball, two minutes on the clock and a 92 percent chance of winning the game. The Titans held again, and got the ball back with about a 15 percent chance of winning.
In a few plays, they had turned the tables. Locker hit Washington again, this time for 40 yards. That one play swung the Titans' chances of winning from five percent to 61 percent as they had the ball on the five-yard line with just under 10 seconds to play.
In essence, the Titans could be expected to score about three of five times from the five-yard line in two plays. Unfortunately, the wild comeback fell short as Locker was sacked on the final play.
In terms of WPA, Jake Locker finished the game at a negative-0.07. This means that if you add up all his good plays and all his negative plays, he "hurt" the Titans' chances of winning by seven percent. Of course, this is highly skewed by the final two plays. He rang up negative-0.61 as the Titans didn't score on the final two plays. Had he thrown the game-winning touchdown, he would have posted a remarkable WPA of 0.93.
Win Probability and WPA are excellent descriptors of clutch situations. They are still in development and the implications are still being fleshed out. How useful they are remains to be seen, but the graphs of incredible comeback games are fun to look at, and the knowledge of these stats can enhance your enjoyment of the sport.