At the Madrid Open, players continued to rely on ball marks to argue with electronic line calling. Tennis needs to find a ...

For years, players used ball marks to understand the story of a match on clay. Now, they are being asked not to trust them.

Daniil Medvedev was agitated—as he sometimes gets. He was having trouble closing out Alexandre Muller, a player ranked 28 spots behind him, in Monte Carlo on Wednesday. At one stage in the second set, ...