I was watching the television broadcast of the semi-final between Djokovic and Sinner at Wimbledon when Andre Agassi, doing the after-match analysis, dropped a line I haven't been able to shake since. In this sport, as in life, hope is fragile but hard to kill. This week on the water I've no idea whether he’s used that sentence in a dozen other broadcasts, tucked in his jacket pocket for the right pause in conversation, or whether it arrived fresh, minted on the spot by a man who has spent a...