Get to Know: Leverage Index by David Appelman March 18, 2008 LI (leverage index): A measure of how important a particular situation is in a baseball game depending on the inning, score, outs, and number of players on base, created by Tom Tango. Baselines: The average LI is 1 and is considered a neutral situation. 10% of all real game situations have a LI greater than 2, while 60% have a LI less than 1. Why you should care: Because LI puts a single number on the importance of a situation, it creates a much simpler and specific way of determining which situations in games are important. It can also be applied to players. See below for various LI player stats: pLI: A player’s average LI for all game events. phLI: A batter’s average LI in only pinch hit events. gmLI: A pitcher’s average LI when he enters the game. inLI: A pitcher’s average LI at the start of each inning. exLI: A pitcher’s average LI when exiting the game. See Critical Situations: Part 3 for more details Additional Links and Resources: Critical Situations Part 1, Part 2, Part 3 Leverage Index Tables We hoped you liked reading Get to Know: Leverage Index by David Appelman! Please support FanGraphs by becoming a member. We publish thousands of articles a year, host multiple podcasts, and have an ever growing database of baseball stats. FanGraphs does not have a paywall. With your membership, we can continue to offer the content you've come to rely on and add to our unique baseball coverage. Support FanGraphs