Know thy opponents — experts make a point of it. When you’re at the bridge table, it’s just as important as knowing your partner, or indeed yourself. Strong players, after all, are far more likely to duck tricks, or play false-cards; weak players are altogether more predictable.
 
An interesting declarer problem came up during a game the other evening, and the following day I bumped into Zia Mahmood and asked what he would have done.