Tennis Match Win Probability Calculator

How it works

P(game from point-prob p) = Σ C(3+j,j)·p⁴·qʲ (j=0..2) + 20·p³q³·p²/(p²+q²) · Set via game-by-game model (tiebreak at 6–6) · Match: best-of-3 = s²(3−2s)

Tennis scoring is hierarchical, so a tiny edge on individual points is amplified stage by stage. Assuming each point is won independently, the game-win formula turns your serve point-win rate into a hold probability; a set is then a game-by-game race to six (win by two, tiebreak at 6–6); and the match stacks sets. Because of this compounding, a server winning 62% of points holds far more than 62% of games — and the match probability sits well away from a coin flip even when points are close.

Worked example

Winning 62% of serve points gives a game (hold) probability near 84%; winning 38% of return points gives a break probability near 20%. Feeding those through the set model yields roughly a 66% set win, which in a best-of-3 (s²·(3−2s)) works out to about a 74% match win probability.

Sources: Tennis scoring & win probability — Wikipedia

Frequently asked questions