This deal was played in the U.S. 2017 Open U.S. Bridge Championship. South held:
♠ A K 3 ♥ J 10 9 8 4 3 ♦ K 8 5 ♣ K
With neither side vulnerable, he dealt and opened 1♥. Left-hand opponent overcalled 1♠ and responder bid 2♠. This promises a limit raise or better in hearts. RHO made a strong spade raise, but South eventually settled in 4♥. The ♦J was led and declarer saw:
Things went poorly. East took the ♦A, South following with the 5. Then East played back the ♦6 to give West a diamond ruff. Now came a club to the ace and another diamond ruff for down one.
So, what’s the point?
Let’s look at the Real Deal:
Without the ruffs, declarer has an easy 11 tricks. With the two ruffs, he was down one. The question is, after trick 2, when West ruffed the diamond, how did West know to cross in clubs and not spades for the second ruff?
East gave a suit preference signal – the ♦6. By returning his lowest diamond, he was suggesting the lowest-ranking side suit, clubs. West obeyed the signal, but declarer was the one at fault. Why?
Declarer followed to the first trick with the ♦5. West carefully watched the spots and observed that partner’s 6 was the lowest outstanding diamond. The ♦4 3 2 were in dummy and declarer had revealed the 5.
Declarer should have hidden his ♦5. If he plays the 8 and king to the first two tricks, West has a guess. Was partner’s 6 a low card from A–9–6? Or, maybe the 6 was a high card from an original holding of A–6–5 (with declarer holding K–9–8).
At least declarer should have made West guess. With everything else he has to do to plan the play of the hand, how can declarer worry about such things? How can he figure this out without thinking forever?
Maybe you have heard that declarer should signal as if he is a defender. If he wants the defender to continue a suit, he encourages.
For example, LHO leads the ace from A–K. Declarer has Q–9–2. He wants LHO to continue the suit, so declarer plays the encouraging 9, standard signaling. By hiding the 2, he makes it hard for LHO to read his partner’s card. West is more likely to continue.
The same thing applies for suit preference. Here, declarer wanted West to play the high suit – spades – at trick three. Accordingly, declarer should have played high diamonds and kept the 5 hidden.