The competitive play of digital games, esports, has attracted worldwide attention of hundreds of millions of young people. Although esports players are known to practice in similar ways to other athletes, it remains largely unknown what factors contribute to high performance and to what degree. In the present confirmatory study, our goal was to test whether deliberate practice theory, which has successfully been applied to other sports earlier, can predict high esports performance with other psychologically relevant variables. The study was carried out with participants from Counter-Strike: Global Offensive (N = 186) and League of Legends (N = 411). In both esports, we found evidence for deliberate practice not having a meaningful effect on performance (null: r > .3 in Counter-Strike: Global Offensive and r > .2 in League of Legends, observed: .02 in Counter-Strike: Global Offensive and -.01 in League of Legends). On the other hand, the results confirmed younger age predicting better performance (-.33 and -.22, respectively). Additionally, we were able to confirm two game-specific findings: attention (-.30, Counter-Strike: Global Offensive) and non-deliberate practice hours (.26, League of Legends) meaningfully predicted performance in one but not both esports. The effects of all other variables—including intelligence, reaction time, and persistence—were confirmed to be null or inconclusive in both esports. We discuss the results against game design and hypothesize esports-specific information density as a potential explanation to differences in performance prediction. The findings can be useful for esports teams, coaches, and all individuals pursuing success in esports.