Mejía-Musetti in Montreal: the match isn't decided in the first set
Lorenzo Musetti is the clear favorite against Nicolás Mejía, and the pick hardly needs arguing: the No. 11 seed against the world No. 129, opening with a second-round debut after a bye. The real technical question is elsewhere, and it's about duration. In his three matches at Washington, Musetti's first tournament after the rectus femoris injury picked up in Rome, the Italian won every first set and lost three of the next four sets. Mejía is exactly the kind of player that number should worry you about.
The Washington curve: 18-4 in first sets, 1-3 after that
The comeback numbers are almost grotesquely lopsided. First sets: 6-0 against Matteo Arnaldi, 6-3 against Aleksandar Vukić, 6-1 against Rafael Jódar. Eighteen games won, four lost. Following sets: one won, three lost.
Against Jódar, in the quarterfinal lost 6-1, 1-6, 4-6 in one hour and fifty-nine minutes, the fracture is measurable on serve. Musetti closed at 44% first-serve percentage, and converted only two of the match's seven break points. When the first serve isn't landing, Musetti's game plan on fast hard courts flips: the one-handed backhand and the variations are there to build the point, not to defend it, and off balance they turn into an invitation.
There is, though, one number pointing the other way, and it's worth saying. Against Vukić he got through two hours and sixteen minutes with no physical issues. The body held up. It's the match rhythm that hasn't come back yet.
One ace in the whole match, and the win anyway
Mejía, in from qualifying, beat Martín Landaluce 4-6, 6-4, 6-3 on a day broken up by rain, becoming the sixth Colombian to win a match in a Masters 1000 main draw. The statistical profile of that win says almost everything about how he plays.
One ace. Just one, against the Spaniard's six. 54% first serves in. And 51% of total points won, the bare minimum margin by which a tennis match can be won. The most telling detail is in the break points: Landaluce converted 60% of his, Mejía 25%. The Colombian wasted more chances than his opponent and won anyway, because he created far more of them.
This is a player who doesn't close points out, he accumulates. He has no shot that hands him free points, so he builds long statistical edges: stay in the rally, return deep, wait for the error. Serving 4-0 in the third set, he let Landaluce claw back to 4-3 and broke straight back. Twenty-six years old, a new career-high ranking, a Challenger title in Bogotá and a second round at Wimbledon: the maturation is no accident.
The hinge point: Musetti's first-serve percentage
Against an opponent like this, there's only one number worth watching. If Musetti stays above 60% first serves, the match ends in two sets and ends early, because Mejía doesn't have the power to hurt him on the first shot, and on the hard courts of IGA Stadium the Italian's serve is worth far more than it is on clay.
If it drops toward 45%, like against Jódar, Mejía gets the match he knows how to play: long rallies, second serves to attack, a third set. And in a third set against a player who has played three matches in two and a half months, the ranking gap counts for much less than it suggests.
Musetti remains the favorite, and in two sets. The pick falls apart if the match reaches a third set with the Italian under 50% first serves: from there on, Mejía becomes a coin flip. The first set, at Washington, never meant anything. The real signal is how many minutes the second one lasts.
