First serve percentage plays a crucial role in determining match outcomes in tennis. A higher first serve percentage typically allows players to dictate the pace and flow of the game, as successful first serves lead to easier points, reducing the chances of quick returns by opponents. When players consistently make their first serves, they are less likely to face break points and can often win points outright or force weaker returns. Conversely, a low first serve percentage can result in prolonged rallies, increased pressure, and vulnerabilities on second serves, leading to higher risks of service breaks.