Relievers: Early 2018 use of leverage index (LI)

Leverage Index (LI) was developed by Tom Tango and measures the amount of swing in the change in win probability indexed against an average value of 1.00. Skip to the pen review if you have heard all of this before. Relievers who come into games in various situations create a composite score around 1.00, when aggregated. Because the average score is indexed to 1.00, relievers with an LI score higher than 1.00 have managers that are showing greater confidence in them to win close games than relievers with an LI score under 1.00.

LI allows us at a glance to identify a developing usage pattern for particular relievers in a given pen far earlier than just scanning box scores and approximating. Games yield very different situations from one...

Almost!

You’re just a few clicks away from accessing this feature and hundreds more throughout the year that have a singular goal in mind: Winning your league. Subscribe to BaseballHQ.com here!

Already a subscriber? Sign in here

More From Relief Pitchers

Identifying the best setup men and projecting their future production.
May 31 2026 3:03am
Closer roles open for the taking as uncertainty reigns supreme in undecided bullpens. Four arms barns are in flux as they determine the best suitor for the challenge of the final frame.
May 24 2026 3:10am
Injuries and ineffectiveness keep the waiver wire moving. Four pens with changes and a look at who else might change soon.
May 10 2026 3:07am
This column took the best K-BB% relievers and filtered for xERA and HR/F as well to create a list of who performed in April.
May 3 2026 3:06am

Tools