Pythagorean record
also: Pythagorean expectation · expected win percentage
The win percentage a team's runs scored and allowed predict, which says how much of its record was luck in close games.
Formula
win% = RS^1.83 / (RS^1.83 + RA^1.83)Teams that outscore their opponents by a lot win a lot, and over a season the relationship is tight enough that the gap between the actual record and the Pythagorean one is mostly one-run-game luck and bullpen sequencing.
We use the 1.83 exponent. A team well above its Pythagorean record tends to fall back toward it.
The common mistake
Early in a season one blowout moves it a lot. It is a season-scale tool.
Where to get it
Related
Pythagorean record from the API
500 free credits on signup, no card. REST or MCP.
Get a free key