Wednesday 8 August 2007

Asking The Right Questions

Doing good simulations is all about asking good questions; finding their answers is the easy part. For instance, you might be fooled by the preceding posts into thinking that partner's heart length is the key to this deal but that isn't necessarily so. All that we've said is that if we know partner has four hearts, we would prefer to play in a heart game than in 3NT. This is a very specific question and, as such, doesn't yield the most useful of answers. I know this hand is pretty boring, but we'll stick with it for now and go even deeper into the analysis.

Let's throw some stats at you, split up into when partner has four hearts and when he doesn't.

2-3 hearts 4-5 hearts
any 4 spades 69% 36%
4 spades and 5+ spade points 40% 20%
any 3+ spade points 83% 78%
any 5+ spade points 48% 38%

What this says is that if partner has 2-3 hearts he'll have a quality spade stopper (AJxx or KQxx or better) 40% of the time. But if he has 4-5 hearts then this probability halves to 20%. Surprise, surprise — suit holdings aren't independent of each other. Holding length in one suit diminishes the chance of holding length in another. And holding length in one suit diminishes the chance of holding high cards in another.

This doesn't change the other analysis, but it's important not to get confused by what it's telling us. It is still correct to say that if partner has four hearts we would prefer to play in 4 than 3NT (marginally) but the over-riding factor may not be heart length at all — it may just be something that influences heart length. Like the quality of the spade stopper.

In other words, splinters are good over 1NT.