waveforms / tools
Elo gap, expected score.
Compare two ratings or enter the gap. See what the difference means.
Positive: A is higher rated. Negative: B is higher rated.
−1,000Equal+1,000
Use ratings from the same rating system and time control.
Expected share of points
Player A is 200 points higher
75.97%
24.03%
A win earns 1 point, a draw ½, and a loss 0. Expected score includes draws; it is not the chance of winning a single game.
How it’s calculated
E(A) = 1 / (1 + 10^(−gap / 400))Gap = rating A − rating B. Player B’s expected score is 1 − E(A). This uses the standard logistic Elo model, with no rating-gap cap or color adjustment. Individual rating systems may use different rules.
The gap curve
Player A’s expected score as the rating advantage changes.