Pythagorean Expectation Formula:
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The Pythagorean expectation is a sports analytics formula originally developed by Bill James to estimate how many games a baseball team "should" have won based on runs scored and allowed. It has since been adapted for other sports with different exponents.
The calculator uses the Pythagorean expectation formula:
Where:
Explanation: The formula estimates what percentage of games a team should win based on their run differential, then applies this to the actual number of games played.
Details: Comparing actual wins to Pythagorean expected wins helps identify teams that may have been lucky or unlucky during a season. Consistently outperforming the expectation may indicate superior bullpen or clutch performance.
Tips: Enter runs scored and allowed (must be positive numbers), select an appropriate exponent (1.83 for baseball, other sports use different values), and enter total games played.
Q1: What's the standard exponent for baseball?
A: The original exponent was 2, but 1.83 has been found to be more accurate for modern baseball.
Q2: How is this used in other sports?
A: Basketball typically uses 14, football 2.37, and hockey 2. Different exponents account for scoring variance between sports.
Q3: What does it mean if actual wins exceed expected wins?
A: The team may have been "lucky" or particularly good in close games. The opposite suggests "unluckiness" or poor performance in close games.
Q4: Can this predict future performance?
A: Teams that significantly outperform their Pythagorean expectation often regress toward it in future seasons.
Q5: What are limitations of this formula?
A: It doesn't account for game-by-game variance, strength of schedule, or roster changes during the season.