A player's serve percentage significantly impacts their overall performance in tennis by influencing their ability to win points and control the match. A higher serve percentage generally indicates a player's consistency and effectiveness in getting their first serve in, leading to more advantageous positions in points and reducing the pressure of double faults. Conversely, a low serve percentage can lead to more break opportunities for the opponent and disrupt a player's rhythm, often resulting in a higher likelihood of losing games and ultimately affecting the match outcome.