Thursday, September 15, 2005 10:24 AM

Hand Evaluation - DNA Analysis

PITBULLS:

The DNA molecule that makes up all Bridge hands are patterns. Each hand has their own particular DNA . DNA analysis in Bridge is to discover which of the 39 building blocks the cell structure of the particular hand has that concerns you. The analytical tools at your disposal are bidding , opening leads , signals & the simple act of following suit or showing out. Here are 3 hands that show how Bridge scientists discover the DNA of a particular hand. Your microscope is using your brain to translate bidding , opening leads , showing out of a suit & signals into hand patterns.

You are in 7NT vul playing the last hand of an important KO event. You get the spade 10 lead , the hands are as follows:

♠ AKx ♥ Qxx ♦ AQx ♣ AQ109 Dummy

♠ Qxx ♥ AKx ♦ KJx ♣ Kxxx You

This hand looks pretty simple. The only thing that can go wrong is a 4-1 club break but from which side ? DNA analysis to the rescue. Lets discover if we can what DNA molecule the opponents have that make up their two hands. Let’s start with the spades. You cash 3 rounds , RHO shows out discarding a diamond. The spade molecule is 5-3-3-2 . We have discovered that LHO has 5♠’s in her hand pattern that makes up her DNA structure. How about hearts ? You cash all your hearts & everybody follows with LHO playing the heart jack. OK let’s try diamonds next , the suit in which west discarded. Everybody follows to diamonds so that DNA molecule is complete. 4-3-3-3 so LHO had 3 diamonds. We do not have a complete analysis of the LHO molecule but we getting close enough to guarantee our contract. 5-3-3-? As LHO cannot hold more than two clubs , we are home ! You go to the board , cash the club Ace & queen & LHO shows out ! The final analysis 5-4-3-1 so RHO gets finessed out of her club jack to bring the contract home. DNA analysis resulted in a vulnerable grand slam making.

Two recent hands from matchpoints where Tom Gandolfo played the role of scientist. Tom is in 5♦X which he must hold to down 3 NV against the vul 4♠ game.

♠ xx ♥ x ♦ Kxxxx ♣ AQxxx Dummy

♠ Qxx ♥ xxxxx ♦ J1098 ♣ x Tom

The auction went 1♥-2NT-3♠-5♦ P-P-X-P . They lead a small spade , RHO cashed the spade AK followed by playing Ace then a small heart which Tom ruffed on the board. Tom noted that although LHO opened the bidding , the doubler has shown up with ♠AK & an ♥Ace thus far. Does this give the opener the Ace & queen of diamonds ? DNA analysis required to answer that question. Tom played the club Ace & ruffed a club back to his hand so noted that the club king which must be in openers hand did not fall. Tom cashed the spade queen, LHO followed with the jack. OK opener is 3-5-? With at least 3 clubs so Tom leads the diamond jack , LHO plays small do you finesse ? Not if your DNA analysis is correct , as LHO can only hold two diamonds & the ♦Q did not pop ! Tom goes up with the King , it wins so Tom plays a small diamond then the diamond queen & Ace collide for all the matchpoints.

Tom again in matchpoints playing for the all important overtrick.

♠ J10xxx ♥ A ♦ xx ♣ AQ987 Dummy

♠ AQxxxx ♥ Kxx ♦ x ♣ Jxx Tom

I opened a club , Tom responded a spade with his LHO pre-empting 3♦ . We reached 4♠ , LHO led a diamond to the Ace & returned a spade. Tom looked at it suspiciously , went up with the Ace . LHO obliged with the King ! Now how do you play the clubs for all the matchpoints ? DNA analysis is always appropriate when the opponents have pre-empted. They have given you information about a 7 card suit. So let’s give LHO 7 diamonds & he has shown up with 1 spade. Let’s continue with the analysis by playing hearts first. You go to the heart Ace , ruff a diamond. You cash the heart king & discard a club. You ruff a heart , LHO follows so you return to your hand with a trump. The DNA analysis has uncovered 1-3-7-? LHO cannot hold more than two clubs . To make the rest of the tricks you must play for a doubleton club king on side which was the case. You play small , insert the queen & play the club Ace dropping the King for +680 so a top. DNA scientist or Bridge player ? The gap is decreasing .

In order to play hands like above or defend like an expert , you only need to acknowledge one pattern of patterns . 2-4-4-3 . Thinking patterns from the “top-down:” , the first digit in this pattern represents 7 card suits , then 6 , 5 & finally 4 card suits. 7-2-2-2 , 7-3-2-1 & 6-3-3-1 , 6-3-2-2 , 6-4-2-1 , 6-5-1-1 & 5-3-3-2 , 5-4-2-2 , 5-4-3-1 . 5-5-2-1 & 4-4-3-2 , 4-4-4-1 , 4-3-3-3 . Just memorize these 13 hand patterns & you are on your way to become a Bridge DNA scientist !!! Do it !