♣♦ Double Asymmetries ♥♠ A First Look >>

# Introduction

We've all seen contracts which can make more tricks declared from one side than the other. A typical example is:
 ♠ A K ♥ K Q 10 9 ♦ A K 10 9 8 ♣ 9 8
 ♠ J 10 9 8 ♥ 8 7 6 ♦ 7 6 5 ♣ A Q 7

 ♠ 7 6 5 4 ♥ J 5 ♦ 4 3 ♣ J 10 6 5 4
 ♠ Q 3 2 ♥ A 4 3 2 ♦ Q J 2 ♣ K 3 2
If North declares 6 NT or 6 , East can set it with a club lead. But when declared by South, both slam makes, scoring five diamonds, four hearts, and three spades.
The K-3-2 holding is an asymmetric guard - a holding which can only be profitable attacked from one side.
This idea led me to ask the question, "Are there deals which play better by North in, say, hearts, but better by South in notrump?"
Here is just such a deal:
 ♠ Q 4 ♥ A K Q J 9 2 ♦ 4 ♣ A 8 6 5
 ♠ 8 6 ♥ 7 4 3 ♦ K 3 ♣ Q J 10 9 7 3

 ♠ J 10 9 5 ♥ 10 6 5 ♦ Q 9 8 6 5 2 ♣ —
 ♠ A K 7 3 2 ♥ 8 ♦ A J 10 7 ♣ K 4 2
In choosing between grand slams, obviously South cannot declare the heart contract - West could give his partner a ruff immediately.
On the other hand, North can easily make 7 , by drawing trumps then setting up the spades with one ruff.
What about the 7 NT contract? On a non-diamond lead, 7 NT can be made. Declarer simply cashes his top black cards then runs his hearts, getting to this position:
 ♠ — ♥ 2 ♦ 4 ♣ 6
 ♠ — ♥ — ♦ K 3 ♣ Q

 ♠ J ♥ — ♦ Q 9 ♣ —
 ♠ 7 ♥ — ♦ A J ♣ —
This is the standard double-squeeze position. On the last heart, East must keep his spade, and therefore must pitch a diamond. South's spade is then pitched, and West must give up in clubs or diamonds.
But what of a diamond lead? When led by East, the diamond lead does, indeed, ruin declarer's chances. When led by West, declarer's double squeeze vanished, but is replaced by a simple squeeze.
Why is that? Because the lead from the West hand requires one of East or West to commit a diamond honor to the first trick. This leaves only one defender guarding the suit.
For example, if West leads the K, South wins in hand, cashes his two top club tricks, and runs his hearts to this position:
 ♠ Q 2 ♥ 2 ♦ — ♣ 8 6
 ♠ 8 6 ♥ — ♦ 3 ♣ Q J

 ♠ J 10 9 5 ♥ — ♦ Q ♣ —
 ♠ A K 7 2 ♥ — ♦ J ♣ —
On this last heart, East is squeezed in spades and diamonds.
If West instead opened with a low diamond, East would have to contribute the Q, and West would be squeezed at the end in diamonds and clubs.
This first example of an Asymmetric Deal employs a cop-out - East's void is what makes the 7 contract fail. Declarer's club holding can hardly be called an asymmetric guard. The rest of the examples will show more subtle types of positions. Most of these hands require careful study for each of the four (sometimes six!) possible contracts under discussion. In these deals, both declarer and the defenders often have to walk a very thin line to maximize their results.
Fundamentally, these are double-dummy problems, so I will not try to construct auctions, or explain what might lead a declarer to take one line over another. I am not so accomplished a bridge writer that I can create such fictions and not make them seem forced. It is unlikely that many of the lines described herein would be found at the table.

### Finding Deals

Doubly asymmetric deals are rare, and require an eagle eye. Thankfully, I can employ a computer's eagle eye. I have employed two computer programs:
• Deal, my own flexible dealer.
• GIB, a double dummy solver written by Matt Ginsberg.
• More recently, I've been using the newest version of Deal which includes a builtin double-dummy solver.
I've written an interface between Deal and GIB which allows me to find deals with interesting double-dummy properties.
Once the deals were found, I sifted through them myself, and extracted what I thought were the most interesting examples. I hope you enjoy them.
 Thomas Andrews (bridge@thomasoandrews.com), © 2000-2009. A First Look >>
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