A simple rule change could make professional tennis matches fairer

When you watch tennis, the scoring feels straightforward. Points build games. Games build sets. Sets decide the match. Yet a new analysis suggests that this structure can lead to an unexpected result; the set winner can take the trophy while winning fewer games overall.

Researchers at New York University, Wilfrid Laurier University, and King’s College London say that the mismatch between performance and outcome is rare but real. Steven Brams at New York University, Marc Kilgour at Wilfrid Laurier University, and Mehmet Mars Seven at King’s College London studied more than 50,000 Grand Slam singles matches from 1968 to 2024. Their paper appears in the Journal of Sports Analytics. They found that game-set discrepancies happen about 3% to 5% of the time across Grand Slam play.

In those matches, the official winner takes more sets. The opponent, however, wins more games across the full match. The authors argue that, in those cases, both players can make a legitimate claim to superiority. One player won according to the rules of the game. The other performed better by a broader count of games won.

The researchers point to a famous example that many fans still debate. In the 2019 Wimbledon men’s final Novak Djokovic beat Roger Federer in five sets despite Federer winning more games overall (36–32), giving Djokovic the champion’s trophy.

Brams, Kilgour, and Seven propose a limited rule add-on they call “The Grand Tiebreak”. Their idea keeps the usual Grand Slam format intact. Men still play best-of-five sets. Women still play best-of-three sets.

The extra step appears only in a specific circumstance. If the match winner by sets has won fewer total games than the opponent, the match would not end immediately. Instead, the players would participate in a final tiebreak to determine the champion.

The authors say the tiebreak should use standard set tiebreak rules in tennis. They also argue that the mere possibility of this tiebreak could change how players approach lopsided sets. If every game can affect the match outcome, a player has more reason to fight for each hold or break.

To understand why mismatches happen, the study models tennis from the point level upward. It uses Markov chains, a probability framework often used to represent step-by-step processes. In this approach, a match is not treated as one block. Each point shifts the score “state,” and those shifts accumulate into games, then sets, then match outcomes.

That modeling also helps isolate what does not drive the mismatch. The paper revisits the old question of whether serving first in a set creates an inherent edge. Under standard assumptions, the authors support earlier work suggesting serving first does not create a lasting set advantage.

The mismatch comes from something else. Sets are discrete wins, and they can be captured efficiently. A player can drop a set badly, then win two sets narrowly. In that pattern, the set tally favors the narrow-set winner. The game tally can favor the player who won the blowout set.

The authors estimate, using modeling, that mismatches occur in about 5% of men’s best-of-five matches and about 3% of women’s best-of-three matches. In real Grand Slam data, they still found hundreds of affected matches in the Open Era.

They also argue the risk rises later in tournaments, when opponents are closer in ability. Early rounds include many uneven pairings, which often end in straight sets. And straight-set matches cannot produce the mismatch the paper targets.

The authors place their proposal in the sport’s longer history of rule updates. “Tennis has a long and venerable history, so why are we suggesting a rule change now?” they write. “First, tennis has not been immune to rule changes; over the last 50 years, one of the most significant was the tiebreak after a set ties at 6–6.”

“This solved a serious problem of extraordinarily long matches, sometimes lasting more than a day,” they continue. “We think that the 2019 Wimbledon final highlights the problem that the strengths of two players may well be gauged by different and equally valid performance measures. A Grand Tiebreak will force players to try to succeed according to both measures, so its existence is likely to greatly diminish the need for it.”

Their argument is not that sets should be discarded. It is that tennis could add a narrowly triggered backstop. In their view, that backstop would resolve the rare moments when the sport’s chosen metric and a common-sense metric disagree.

If governing bodies adopted a Grand Tiebreak, you would likely see strategy shift in subtle ways. Players could feel stronger pressure to avoid “coasting” through a set that looks lost, because each extra game could prevent a later mismatch trigger. That may raise the intensity of matches, especially in later rounds.

The research also offers a clearer way to discuss fairness in sports systems. You can apply the same idea to other competitions where one scoring layer overrides another.

For analysts, the study shows how large match databases and probability models can reveal edge cases that rules never anticipated. For fans, it highlights why a champion can look dominant by sets and less dominant by games, without any contradiction in the rules.

Research findings are available online in the Journal of Sports Analytics.

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