Carleton: Is win probability broken?

From Russell Carleton at Baseball Prospectus on February 21, 2017:

It’s probably a sign of how long we’ve been without baseball that this week’s column was inspired by football. A couple of weeks ago, the Annual Ultimate Flying Handegg Game of Doom was played, and since I live in Atlanta I was vaguely aware of one of the teams playing in the game. According to conversations that I overheard at the water cooler, the Falcons were up 28-3 at one point, but didn’t win. According to various win probability models of football, at one point the Falcons were considered to have a 99 percent chance to win the game. Of course, that didn’t actually happen. So, can we believe win probability models anymore?

There has also been another well-documented recent case of a win probability model put forth by a prominent alumnus of this site that said the blue team was likely to win, but it turned out that the red team actually won that one.

In football, like in baseball, there’s really only so far that you can go to build a win probability model. There is data from previous games to look at, and I suppose we can look back on some combination of the score, possession of the ball, field position, and the time remaining in the game and figure out how often a team in that situation won. But in this particular case, it was the Super Bowl. The other team, even though down by a bunch of points, is in this game by definition because they are really good at playing football. The teams that were likely to fall behind 28-3 in a random regular season game are probably the bad ones. Are they a good comparison group for the conference champions? Or is this just a case where there might have been a 99 percent chance of winning, but … hey, there was always a chance.

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Originally published: February 21, 2017. Last Updated: February 21, 2017.