In any sport, a sense of elation is a dangerous thing. When a player does something good, he can’t afford to enjoy the moment: however dazzling the goal he’s scored or the ace he’s served, he can’t relax until the match is over. And so it is in bridge. It’s hard advice to follow: I’ve often lapsed into a smug reverie mid-hand upon doing something clever — and the next thing I know, everything’s fallen apart.