Making tennis fairer: The grand tiebreak <sup/>

Tennis, like other games and sports, is governed by rules, including the rules that determine the winner of points, games, sets, and matches. If the two players are equally skilled, each has an equal chance of winning matches. However, the player who wins the most games may not be the player who wins the match. A notable example was the 2019 men's Wimbledon final between Novak Djokovic and Roger Federer. In this paper, we study both theoretically and empirically the probability of such discrepancies occurring, using data from 50,000 Grand Slam matches. We argue that this discrepancy, when it occurs, should be resolved by a Grand Tiebreak (GT)—played according to the rules of tiebreaks in sets—because each player has a valid claim to being called the rightful winner. A GT would have the salutary effect of giving each player an incentive to strive hard to win every game—even every point—lest he/she win in sets but lose more games. This would make competition keener throughout a match and probably decrease the need for a GT, because the game and set winner would more likely coincide when the players fight hard for every game and point.