Double when they don't have any tricks

I think I've learnt something about doubling lately. I used to ask myself 'how many tricks have I got'. It seems very reasonable, after all the more tricks I had the smoother the defence and the bigger the penalty.

So often though you don't have that many tricks. You don't double and it turns out that they didn't have many tricks either.

♠	T 5 2
♥	3
♦	K Q T 3
♣	A T 7 6 5

Fourth in hand and all vul the auction starts quickly, (1♠) - 4♥ - (4♠). How many tricks do you have? Two? A diamond and a club is all you count for sure. Hopefully partner has a trick, that makes three.

Stop. How many tricks do they have? Lets award partner something like the KQ of hearts and a minor suit Jack. Still only three tricks for us but how many for them? If you think 1 in each minor and 1 heart your pass must say that you expect they'll take 7 spade tricks. Who's to say they haven't overstretched:

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

The key is that none of your values are in spades or in hearts. You're unlucky if partner has neither the ♥A nor a singleton club. Then it will go down immediately.


Back to more normal bidding:

♠	K 2
♥	K 5 3
♦	K T 8 2
♣	A J 8 7

You deal and the auction begins 1♣ - (pass) - 1♦ - (1♠)
1NT or 2♦?