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-WDlr: 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.