Gender and surface effects on tiebreak tactics in Grand Slams: A machine learning-enhanced point-by-point analysis.

Purpose: Tiebreaks in professional tennis are high-pressure situations in which tactical execution may influence match outcomes. This study investigated how gender and playing surface are associated with tactical behavior and point outcomes during tiebreaks in Grand Slam singles matches. Methods: Using a dataset of 51,665 tiebreak points from 4347 matches played between 2011 and 2024 across the four Grand Slam tournaments, we applied a two-level analytical framework. First, set-level comparisons were conducted across 12 subgroups defined by gender, surface, and outcome. Second, point-level XGBoost models were developed separately by gender and surface, and SHAP values were used to interpret the contribution of 13 tactical predictors. To examine the effect of within-tiebreak dependency, an additional tiebreak-level grouped validation was performed. Sensitivity analyses were also conducted after excluding super tiebreaks. Results: Set-level analyses showed significant winner-loser differences in several technical-tactical indicators, particularly Serve Points Won, Winners, and Unforced Errors, with patterns varying by gender and surface. Under the original random split, point-level model accuracy ranged from 0.634 to 0.710 and AUC from 0.625 to 0.747 across subgroup models; under tiebreak-level grouped validation, the corresponding ranges were 0.637-0.700 and 0.595-0.752. SHAP analysis identified PointServer as the most consistently important predictor across subgroup models, whereas the relative importance of other variables-including RallyType, ServeWidth, ReturnDepth, and net-related indicators-varied by gender and surface. Sensitivity analyses excluding super tiebreaks showed trivial effect sizes at both the set and point levels. Conclusion: Tactical behavior in Grand Slam tiebreaks was associated with gender and surface context. Male grass-court tiebreaks were more strongly characterized by serve-dominant patterns, whereas female clay-court contexts showed greater relevance of rally control and error management. These findings provide retrospective, interpretable evidence on context-specific tactical tendencies and may serve as a useful reference for match preparation, post-match review, and performance analysis.