The balls changed in March. The tour has been arguing about it since. The data is less ambiguous than the arguing: serve speed is up four percent, rally length is down nine.
What changed
A lighter felt, which the manufacturer describes as a durability improvement and the players describe as a different sport.
// The season in numbers
+4%
Average first-serve speed
−9%
Average rally length
+11%
Aces per match
Who benefits
Tall servers, obviously. Less obviously, returners who stand deep — the ball arrives faster but sits up, and the players who have adjusted are winning return games at last year’s rate.
