Which suit should partner lead to you?

Ann Richards, the 45th Governor of Texas, who died in 2006, said, “I have very strong feelings about how you lead your life. You always look ahead, you never look back.”

At the bridge table, the previous tricks cannot be changed, but they influence tricks still to come. In this deal, for example, South is in four spades. West leads the heart ace. What happens after that?

South has a textbook three-spade opening, showing a good seven-card suit and 5-10 high-card points. North’s raise is thin, but it is worth gambling for a vulnerable game.

At trick one, East must play the heart nine, starting a high-low (echo) with his doubleton. West cashes the heart queen and continues with the heart king. What should East discard?

Assuming the third heart is standing up, South’s hand presumably has one of these distributions: 7-3-2-1, 7-31-2, 7-3-3-0 or 7-3-0-3. In the first three cases, East wants his partner to shift to a diamond at trick four, not to a club. (Yes, if West has exactly queen-doubleton of clubs, a club switch produces down two, whereas a diamond shift defeats the contract by only one trick.) Any club tricks can wait, but the diamond king needs to be established. So, East should discard the diamond nine. He could throw the club four, but it is better to signal with a high, encouraging card in the suit he would like partner to lead.

If West shifts to a diamond at trick four, the contract fails. If, though, he leads a club, declarer loses that trick, but gets his diamond loser away on the dummy’s club king.