{"as_of":"2026-09-14","attribution":"Live Tennis API \u2014 https://livetennisapi.com","licence":"CC BY 4.0 \u2014 free to reuse with attribution to Live Tennis API","method_note":"Completed best-of-three singles matches on ATP, WTA, Challenger and ITF, 2023-01-01 to 2026-09-14. Retirements and walkovers excluded. Counted from the point-by-point tape, not estimated.","studies":[{"article":"https://blog.livetennisapi.com/blog/tennis-first-set-comeback-rate","best_of_five":{"comeback_pct":23.98,"matches":1597,"tour":"ATP"},"breakdown_note":"Two of these columns do not sum to 116,382 and the reasons differ. by_surface (113,288) genuinely excludes matches whose surface the feed never stated: a 2026-09-16 re-measurement puts that at 3,100 against the 3,094 implied here. by_tour (116,371) and by_first_set_score (115,874) SHOULD each sum to the corpus \u2014 the re-measurement finds no seventh tour and no eighth scoreline \u2014 so their shortfalls are counting drift in the published rows, not exclusions. Every RATE reproduces: ATP, WTA and both Challenger tiers match exactly, and no first-set rate moves by more than 0.02 percentage points.","by_first_set_score":[{"comeback_pct":21.92,"margin_games":1,"matches":14265,"set":"7-6"},{"comeback_pct":19.41,"margin_games":2,"matches":25546,"set":"6-4"},{"comeback_pct":18.89,"margin_games":2,"matches":10252,"set":"7-5"},{"comeback_pct":17.39,"margin_games":3,"matches":25970,"set":"6-3"},{"comeback_pct":13.3,"margin_games":4,"matches":19739,"set":"6-2"},{"comeback_pct":11.06,"margin_games":5,"matches":14269,"set":"6-1"},{"comeback_pct":7.18,"margin_games":6,"matches":5833,"set":"6-0"}],"by_surface":[{"comeback_pct":17.2,"matches":3593,"surface":"grass"},{"comeback_pct":16.79,"matches":47944,"surface":"clay"},{"comeback_pct":16.47,"matches":61751,"surface":"hard"}],"by_tour":[{"ci95_pp":0.72,"comeback_pct":18.21,"matches":10945,"tour":"ATP"},{"ci95_pp":0.43,"comeback_pct":17.32,"matches":30406,"tour":"Challenger M"},{"ci95_pp":1.08,"comeback_pct":17.25,"matches":4731,"tour":"Challenger W"},{"ci95_pp":0.63,"comeback_pct":17.04,"matches":13543,"tour":"WTA"},{"ci95_pp":0.42,"comeback_pct":15.97,"matches":29331,"tour":"ITF W"},{"ci95_pp":0.42,"comeback_pct":15.18,"matches":27415,"tour":"ITF M"}],"id":"first-set-comeback","matches":116382,"overall_comeback_pct":16.52,"title":"Comeback rate after losing the first set"},{"article":"https://blog.livetennisapi.com/blog/tennis-first-set-comeback-rate","id":"second-set-win-probability","note":"Chaser = the player who lost the first set. Each state counted once per match.","states":[{"chaser_wins_pct":58.53,"matches":3682,"score":"6-1"},{"chaser_wins_pct":56.38,"matches":5044,"score":"6-2"},{"chaser_wins_pct":52.19,"matches":8943,"score":"6-3"},{"chaser_wins_pct":50.16,"matches":8132,"score":"6-4"},{"chaser_wins_pct":45.22,"matches":8755,"score":"3-0"},{"chaser_wins_pct":39.02,"matches":18412,"score":"3-1"},{"chaser_wins_pct":36.8,"matches":16660,"score":"2-0"},{"chaser_wins_pct":31.93,"matches":11369,"score":"6-5"},{"chaser_wins_pct":27.31,"matches":30218,"score":"3-2"},{"chaser_wins_pct":25.38,"matches":38611,"score":"2-1"},{"chaser_wins_pct":23.64,"matches":53887,"score":"1-0"},{"chaser_wins_pct":21.13,"matches":22506,"score":"5-5"},{"chaser_wins_pct":19.47,"matches":33832,"score":"3-3"},{"chaser_wins_pct":17.66,"matches":63405,"score":"1-1"},{"chaser_wins_pct":16.52,"matches":116382,"score":"0-0"},{"chaser_wins_pct":10.42,"matches":47102,"score":"1-2"},{"chaser_wins_pct":10.36,"matches":61626,"score":"0-1"},{"chaser_wins_pct":10.19,"matches":37473,"score":"2-3"},{"chaser_wins_pct":9.51,"matches":31243,"score":"3-4"},{"chaser_wins_pct":8.17,"matches":26514,"score":"4-5"}],"title":"Win probability by second-set score, after losing the first set"},{"article":"https://blog.livetennisapi.com/blog/tennis-hold-rate-by-surface","by_surface":[{"games":74673,"hold_pct":74.43,"surface":"grass"},{"games":1222994,"hold_pct":69.95,"surface":"hard"},{"games":941773,"hold_pct":65.98,"surface":"clay"}],"by_tour":[{"games":230715,"hold_pct":78.62,"tour":"ATP"},{"games":622018,"hold_pct":74.1,"tour":"Challenger M"},{"games":529948,"hold_pct":70.26,"tour":"ITF M"},{"games":266503,"hold_pct":64.36,"tour":"WTA"},{"games":92396,"hold_pct":60.4,"tour":"Challenger W"},{"games":553157,"hold_pct":58.93,"tour":"ITF W"}],"id":"hold-rate","service_games":2239440,"service_games_note":"2,239,440 counts only matches with a known surface \u2014 it is the denominator of by_surface, which sums to it exactly. by_tour covers the full corpus and sums to 2,294,737; the 55,297 difference is matches whose surface the feed never stated.","title":"Service hold rate by surface and tour","validation":"Reproduces the widely published ATP (~79%) and WTA (~64%) hold rates on a method tuned to neither; tiebreak games excluded."},{"article":"https://blog.livetennisapi.com/blog/tennis-hold-rate-by-surface","by_surface":[{"matches_with_tiebreak_pct":31.73,"sets_to_tiebreak_pct":15.91,"surface":"grass"},{"matches_with_tiebreak_pct":25.28,"sets_to_tiebreak_pct":12.31,"surface":"hard"},{"matches_with_tiebreak_pct":22.52,"sets_to_tiebreak_pct":10.72,"surface":"clay"}],"id":"tiebreaks","title":"Tiebreak frequency by surface"}]}