Houston Texans' Advanced Stat of the Week: Win Probability

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.

The Texans' miracle win at Cincinnati last year illustrates this nicely.

The teams swapped field goals early, but a Ben Tate fumble on the goal line tilted the odds towards Cincy. By half time, the Bengals had built up a 16-3 lead, and the Texans were left with just a one in 10 chance to pull out a victory on the road.

A big play on defense helped Houston stay alive. Connor Barwin forced an Andy Dalton fumble, and the Texans converted for a touchdown to make it a six point game. There was still a 66 percent chance that the Bengals would win, but this was as tight as the game would get until the final minutes.

The Bengals would tack on a field goal, and their odds of winning hovered between 80 and 90 percent for the bulk of the second half. Even a Houston field goal with just over five minutes left didn't help much. At that point, Cincinnati was still an 86 percent favorite.

The Bengals didn't do a bad job of running out the clock, but couldn't quite finish the job. Facing a fourth and one at their own 48 with 2:43 to play, they punted. The Texans took over with more than two minutes on the clock, down six and with no timeouts. They had a one in four chance of winning.

Things got worse for Houston before they got better. While T.J. Yates methodically moved the ball, he took a sack on second down with 1:15 left. Facing a third and 15, the Texans' odds had again fallen to just 10 percent.

Yates was not to be stopped, however. He scrambled 17 yards for a first down and, after an incompletion to Owen Daniels, managed to get a pass interference call moving the ball down to the six.

Two plays later, the Texans had a touchdown and their first division crown. With just six plays (one of which was a spike), Houston had jumped from a 10 percent chance of winning to a 99 percent chance.

Yates finished with game with a nearly perfect WPA score of 0.98, reflecting the fact that all the plays at the end depended on his efforts. WPA masked some of the inconsistency in his game, because if the Texans had lost at the end, his score would have likely been negative -0.02.

Miracle comebacks aren't thrilling because of crazy numbers, but after the cheering is done, it can be fun to see just how unlikely the win was. Win Probability and WPA aren't necessarily predictive stats, but they are an enjoyable descriptor after the fact.