: A critical difference between winning and losing players is their success rate on second serves . Winning players are often able to maintain or even improve their point-win percentage on second serves during break points, while losing players cannot maintain their level.
: Some statistical models suggest that the first game of a match is the hardest one in which to achieve a break of serve. Tennis serve performances at break points - ResearchGate break of serve
: Research published in Journal of Sports Science & Medicine notes that while first-serve effectiveness varies by surface ( on clay vs. : A critical difference between winning and losing
: Despite trying to play safer, players produce double faults twice as often at break points ( ) compared to regular points ( Other Notable Research Perspectives Tennis serve performances at break points - ResearchGate
A key academic paper on this topic is by researchers from the University of Vienna and University of Munich.
: Under the pressure of a potential break, players often hit their first serves faster but decelerate their second serves to avoid double faults.