This data is from MLB games from 1903-2023, including postseason games. Data are complete back to 1973, mostly complete back to 1950, and somewhat complete back to 1916. It omits games that are less than 9 innings (doubleheaders in 2020) as well as extra inning games where a runner starts on second base (non-playoff games since 2020). All data is available at Retrosheet.
Linked from: FiveThirtyEight, The Washington Post, Nate Silver's Silver Report, Jayson Stark's "Weird and Wild" column and on the Starkville podcast (starts around the 83:00 mark), FanGraphs' Effectively Wild podcast (around the 40:30 mark), CBS Sports, CBS Sports again, The Athletic, Royals Review, Beyond the Box Score, Talking Chop, and more!
Articles written with this data:
- How common are walk-off walks (on four pitches!) in baseball?
- How likely are walks and strikeouts by count?
- How often does a bases loaded no out situation end with 0 runs?
- How unlikely are two immaculate innings in the same game against the same batters? (very!)
- Why are so many runs scored in the bottom of the first inning? (also on FanGraphs Community)
- Did the Astros set a record by challenging a play while up 13 runs? (no)
- Does the length of the top of the first inning affect the number of runs scored in the bottom of the first? (somewhat!)
- How effective are teams at manufacturing runs?
Source files available on GitHub.
Idea taken from walkoffbalk.com's Win Expectancy Finder (now defunct). Here's a good article about Win Expectancy. Leverage Index calculations based on this article.
The information used here was obtained free of charge from and is copyrighted by Retrosheet. Interested parties may contact Retrosheet at 20 Sunset Rd., Newark, DE 19711.
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