One of the metrics for evaluating situational hitting is RE24. For those of who aren’t familiar, that stands for Run Expectancy in the 24 base-out states.
RE24 is calculated as the difference in run expectancy before and after a PA, plus any runs that score as a result of the PA. The run expectancies in that calculation are based on empirical results for each base-out state, from nobody on, nobody out to bases loaded, two out. Run expectancy means how many future runs would expect to score in an inning starting from each base-out state, assuming a team of identical average hitters facing identical average pitchers. The run expectancies are pretty intuitive: the more runners on and the fewer the outs, the higher the run expectancy, and vice-versa.
RE24 for a PA can be positive or negative and thus can be summed over a game, a season, or a career. The results apply to both pitchers and hitters. Thus, a positive RE24 for a batter in a given PA is a negative RE24 for the pitcher, and vice-versa. One caveat is that RE24 scores are not adjusted for inning, game score, batting order position, platoon advantage, park effects, or anything else. Thus, RE24 is often most useful when comparing players on the same team.
More on 2013 situational hitting results after the jump. Continue reading →