Win probability

Win probability is a statistical tool which suggests a sports team’s chances of winning at any given point in a game, based on the performance of historical teams in the same situation. The art of estimating win probability involves choosing which pieces of context matter. Baseball win probability estimates often include whether a team is home or away, inning, number of outs, which bases are occupied, and the score difference. Because baseball proceeds batter by batter, each new batter introduces a discrete state. There are a limited number of possible states, and so baseball win probability tools usually have enough data to make an informed estimate.