Guessing diamonds

Playing matchpoints at the local club the morning of May 13, your partner leads the ♠T against the opponents’ contract of 4♥, reached after an auction of 1NT (11-14)-4♦ (transfer) – 4♥.

 

 

 

 

 

 

What is your defensive plan, after you have won the spade opening lead?

With 25 HCP between the two shown hands, and 11-14 promised by declarer, you can place partner with 1-4 HCP.  The lead marks declarer with the ♠J.  Declarer’s opening bid looks pretty barren (but far from impossible) if he does not possess the ♦A, ♣A, and ♣K.  Assuming declarer does own those cards, however, the location of the ♦Q and the ♦T remains uncertain.  Let’s examine the possibilities:

• Declarer owns both the ♦Q and the ♦T.  In this case, you need to cash the second spade; otherwise dummy’s remaining spade could be pitched on a surplus diamond winner.  Just “could” and not “will”, because declarer might well choose to pitch a diamond on the established ♠J, and then cash the ♦A and take a ruffing finesse in diamonds in order to pitch the losing spade from dummy.  In that case, you might merely swap a spade trick for a diamond trick.  “Might” and not “will” because when the ♦Q is not covered, declarer might choose to ruff the ♦Q and, lo and behold, drop your doubleton ♦K, thus establishing the ♦T for a pitch of dummy’s second spade.  Ah, bridge is a tough game, eh?
• Partner owns the ♦Q (with or without the ♦T).  In this case, you need to switch to a diamond.  If you instead continue a spade, the ♦J will be pitched on the established ♠J.
• Declarer owns the ♦Q and partner owns the ♦T.  In this case, you might as well cash the second spade.  Declarer has no surplus diamond winner to pitch the spade (if the ♦J is led from dummy, you cover with the king, declarer can win the first two diamonds, but partner’s ♦T can win the third round of diamonds); no pitch of a spade on a diamond is available. 

Further complication #1.  Diamonds is not the only suit that can produce an extra winner in declarer’s hand upon which he can pitch dummy’s second spade. Clubs also might produce an extra winner: imagine declarer with AKxx of clubs.

Further complication #2.  You realize that at other tables the 4♥ contract will be played by your table’s dummy and not by your table’s declarer.  In that case – at least as I like to play defensive signaling – partner’s discouraging signal on your spade lead should show the ♦Q (or ♦K, if you did not already hold that card), because diamonds is the “obvious shift suit”.  You would be much better positioned to ascertain whether the defense can build a trick in diamonds if you had been on lead.

All in all, I judged it best to cash the second spade.  But a diamond was the winning switch.

We received about an average board, when only two pairs out of 16 defeated 4♥ (hearts was declared by North at all tables other than mine).