In top-level competitions where technical skills are evenly matched, mental strength often determines the winner. Although many studies have examined this strength, its neural basis remains unclear. Esports provides a useful setting for studying mental competition, combining split-second decision-making with psychological strategy. With minimal physical movement, it enables high-precision physiological monitoring in real-world settings, revealing core aspects of performance obscured by motor noise. Using neural, cardiac, and muscular signals recorded during gameplay, we identified brain activity that predicts outcomes and physiological states that distinguish experienced players from true elites. By analyzing these optimal states, we are exploring practical pathways to peak competitive performance.