Stan Wawrinka

Stan Wawrinka plays at 41 as a three-time Grand Slam champion and a fixture of the old guard. The Swiss right-hander, whose one-handed backhand won the Australian Open in 2014, Roland-Garros in 2015 and the US Open in 2016, has 16 ATP career titles and a career-high ranking of No. 3. Wawrinka's results now come in short, stubborn bursts rather than sustained runs.

Age has not erased his baseline firepower, but the win rate tells the true story: losses arrive more often against younger, quicker movers, while his best weeks still surface on clay and indoor hard courts. Wins are no longer automatic against lower-ranked opposition, a sign that the margin for error has narrowed. Yet he remains a dangerous draw, and his matches, win or lose, still carry the weight of a former world top-three player.