A matter of technique

There will no doubt be many fascinating deals in Shanghai over the next 2 weeks.  This one, from Round 3 yesterday, was the first that has caught my eye.         

	♠ K 10 6 5
	♥ A Q
	♦ Q 10 8 7 6
	♣ 9 3
	♠ Q 8
	♥ J 7 6
	♦ K J 9 2
	♣ A K 10 7

You are in 3NT, after West has opened 2♥, and the lead is the ♥5.  How would you play?

It may seem that the key question is which ace does West have, assuming he has one.  If he has the spade ace, you want to play spades before diamonds, and vice versa.  But there is more to it than a 50% guess; indeed, out of over 50 declarers in the three events here, only 6 contrived to go down – although one on Vugraph misplayed the hand badly, and got away with it after two poor defensive plays.

The point, it seems to me, is that you need four diamond tricks and only one spade trick, after the heart queen holds at trick one.  Playing a spade now from dummy has two upsides: 1) you may have guessed right – West may have only the spade ace, and you have removed his entry oto the heart winners; 2) East may well duck the spade ace, in which case you’ll switch to diamonds and romp home with nine tricks.

I know the statistics are flawed, because some of those 2♥ openings may not have happened, and some may have shown a 2–suiter, etc. etc.  But it’s interesting that such a large preponderance of declarers got the 50-50 guess right, suggesting that they may well have followed my reasoning.  Certainly, whole lot more than half of the field played on spades first.

I wonder what would happen in a club game?  This is a deal highly reminiscent of the kind that Mark Horton included in his recent book, Bridge Master versus Bridge Amateur – the kind of situation where the experts always get it right, and the amateur frequently errs.

The full deal:

	♠ K 10 6 5
	♥ A Q
	♦ Q 10 8 7 6
	♣ 9 3
♠ A 2		♠ J 9 7 4 3
♥ K 10 9 5 4 2		♥ 8 3
♦ —		♦ A 5 4 3
♣ J 8 6 4 2		♣ Q 5
	♠ Q 8
	♥ J 7 6
	♦ K J 9 2
	♣ A K 10 7