This study was designed to determine if winning a specific game in a tennis match would predict success in the match and if psychological momentum was influenced by ability levels or gender of the players. Subjects were 119 male and female players competing in 163 matches in three sanctioned tennis tournaments. Game-by-game and set results were recorded. Furthermore, interviews were conducted to ascertain players’ perceptions of momentum. Results revealed that winning any of the first eight games in the first and/or second set was a significant predictor of success in the tennis match. However, when only the results of more competitive matches (when sets extended to nine or more games) were examined, Games 8, 10, and 11 in the first set were significant predictors of winning the match, while only Game 4 of the second set resulted in an increased probability of match victory. No gender or ability differences were found. Based on these findings, it is suggested that investigators be cautious in inferring psychological momentum since these findings were dependent on the equity of competitors within a match, and psychological momentum seems to be a highly individual matter.