Abstract: This study used the methods of questionnaire surveys, Delphi method, video analysis and mathematical statistics to analyze and study the data of 210 games in the Grand Slam Tennis and the Tennis Masters Cup from 2017 to 2021, including 70 games on hard court, clay court and grass court respectively. By introducing a theoretical framework of key performance indicators and establishing discriminant function models, this study identified tactical performance indicators affecting match outcomes of athletes on different court types. The results showed that the models for key tactical performance indicators influencing match outcomes on different court types were as follows: Y (hard courts) = -12.00 + 10.73 × return scoring rate + 8.74 × first serve scoring rate + 4.15 × second serve scoring rate; Y (clay courts) = -13.26 + 13.67 × return scoring rate + 7.53 × first serve scoring rate + 5.68 × winners to unforced errors ratio (W/U); Y (grass courts) = -9.63 + 10.27 × return scoring rate + 4.70 × second serve scoring rate + 4.95 × net scoring rate. The Wilks’lambda statistics for the models were 0.40, 0.31, and 0.45 respectively, with chi-square values of 124.93, 136.43, and 74.58, all having p-values less than 0.05. Conclusion: Key tactical performance indicators on hard courts include first serve scoring rate, second serve scoring rate, and return scoring rate. On clay courts, they include first serve scoring rate, W/U ratio, and return scoring rate. On grass courts, they include net scoring rate, second serve scoring rate, and return scoring rate. Across different court types, return scoring rate is consistently the most influential tactical performance indicator affecting match outcomes.

Key words: tennis player, different courts, training load, tennis techniques and tactics, key performance indicators