How a Tennis Mini Camp Turned Around John Isner’s Year

John Isner will enter the United States Open seeded 11th, seeking to convert a run at Wimbledon into success in New York.TORONTO — In early March, when John Isner was staggering through some of the worst results of his career, Justin Gimelstob invited him to Los Angeles for a much-needed cram session.

Isner had won only two matches in the first two months of the season, yet somehow Gimelstob — the television broadcaster, former professional player and a member of Isner’s three-man coaching staff — was bubbling with confidence.

He consulted David Macpherson and Rene Moller, Isner’s two other coaches, and there was consensus on what was needed. Then, in something akin to a team sport’s mini…