4 + 3 = 7

Author: Larry Cohen
Date of publish: 09/01/2018
Level: Intermediate to Advanced

This deal is from an old IBPA Bulletin. At favorable vulnerability, South held:

♠ --  
♥ KQJ873  
♦ A95  
♣ 10762.
 

Any reasonable method of hand evaluation would lead to an opening bid of 1♠. West preempts with 2♠ and partner bids 3♠ to show a GF heart raise. With 6 beautiful trumps and 2 first-round controls, South should make a control-bid, 4♠. North now jumps to 5♠. What's that? When the opponents have bid a suit, a jump to 5-of-our-major should invite slam if partner can control their suit. With first-round control, opener tries 5♠ and responder jumps to 7♠. A trump is led and you anxiously await the dummy:

♠ 8642
♥ A109
♦ KQ6
♣ AKQ
 
♠ --
♥ KQJ873
♦ A95
♣ 10762

 The only possible loser in your hand is the 4th club. If clubs are 3-3 (or the jack falls), you have 13 easy tricks. If trumps are 2-2, you can ruff the 4th club in dummy. Is there anything better?

You could draw two trump and if they are 3-1, still try the clubs and hope that if an opponent has club length that he is the one with the 3 trumps.

There is something even better. Veteran problem solvers will recognize the chance to reverse the dummy. If you can trump all 4 spades in your hand, you won't have to worry about the long club. After winning the trump lead in dummy (East follows), you ruff a spade. You cross in clubs and ruff a second spade. You can cross in diamonds and ruff a third spade. You can cross in trumps (RHO throws a club) and ruff the 4th spade (RHO throwing a diamond). You have trumped 4 spades in hand and drawn 2 rounds of trump. You are out of trumps, but West remains with one.

How do you cross back to dummy to draw it?

Since you have only 6 diamonds, but 7 clubs, the odds favor crossing in the shorter suit. This works, as you can see from the full deal:

Vul:E-W
Dlr: South
♠ 8642
♥ A109
♦ KQ6
♣ AKQ
 
♠ AQJ1053
♥ 542
♦ 1043
♣ 3
  ♠ K97
♥ 6
♦ J872
♣ J9854
  ♠ --
♥ KQJ873
♦ A95
♣ 10762
 

Drawing trump and hoping for the clubs to come in would have failed. Trumping all 4 spades in your hand was the correct line of play.

A title of "Dummy Reversal" would have been too obvious; I hope that 4 + 3 (4 trumps in hand and 3 in dummy) didn't give away the show.