Winners in accepting their trophies invariably thank their teams, as well as their opponents, the fans, the ball boys and girls, and sometimes their spouses and parents. The teams include nutritionists, perchance psychologists, strength trainers, and even coaches. When coaches and players part often, which seems to happen more on the women’s side than the men’s, you know something is not clicking, but you never know what, though you can guess. Federer and Nadal kept the same coach for most of their careers; Murray and Djokovic tried some variety to adjust for a given stage in their professional evolution or even a specific tournament.