At the US Open and other US-based tournaments, the men and women play with different tennis balls. The men play with the slower heavy-duty felt while the women play with the faster regular-duty felt. – WTF Fun Facts
Source: https://www.wsj.com/articles/at-u-s-open-do-women-play-with-faster-tennis-balls-11565957964
@me So clever bro…
It’s a well-known fact in professional tennis circles that female players don’t like playing with men’s balls.