6 spades or 6NT?
Here's a great hand to start off an EW evening's bridge. A balanced 18 points opposite a balanced 16 – and a spade fit, too. Thing is, would you rather be playing in 6♠ or 6NT?
As so often, it all boils down to the final trick. In either contract, you've got 11 tricks off the top – 4 in spades, 3 each in clubs and hearts and one in diamonds – so the question becomes: where's your 12th trick coming from (a) in 6♠ and (b) in 6NT?
Well, if the ♦K is with South, it's a doddle in either contract: you simply lead a low diamond towards the ♦Q and there's your 12th trick. If you're in spades, it doesn't matter where the ♦K is. You can give up a diamond trick and then ruffing a third round of diamonds in dummy gets you your 12th trick.
But what do you do in 6NT if the ♦K's wrong? Well, then you have to hope that the clubs are split 3-3. Or that the ♣J's in a doubleton. Or that the ♣J can be finessed.
I can't work out the odds exactly (though better players than I, of which there are very many, will be able to do just that!), but I'd say that the chances of making 6♠ (♦K with South OR trumps 3-2 or in some cases 4-1) are at least 85%. which is pretty good. And the odds of making 6NT (♦K with South OR clubs 3-3 OR the ♣J get-at-able) are near enough the same.
So since 6NT earns you 10 points more than 6S, maybe 6NT is the place to be.
Maybe? Well, yes. 'Cos there's something else going on here, and that's how easy it is to get it right (a) in spades and (b) in NT. In spades it's fairly straightforward: take a couple of rounds of trumps, then attack the diamonds and get your ruff (OK, if the trumps are 4-1, you have to be a bit careful). But in NT, it's much trickier. For a start, do you try the diamonds first or the clubs? (Answer: the diamonds, because they necessarily involve you losing a trick.) And how do you work the clubs? Do you try to drop the ♣J? Or try a couple of rounds and then if it hasn't appeared try to finesse it?
You see what I mean? NT are worth more, but more difficult to play. Spades are worth less, but are easier to play. So the answer is: it's up to you!
The full deal
If you look at the full deal, you'll see that the ♦K is wrong. As we've seen, this doesn't matter two hoots if you're in spades: just give 'em a diamond trick and ruff the 3rd round of diamonds.
But in NT, it's a different story: you test the diamonds and your ♦Q loses to North's King. Now you have to get the clubs right to succeed. And as you can see, if you simply bang out your ♣AKQ, the ♣J doesn't drop ... and that's you one off. To succeed, you have to cash your ♣A, then your ♣Q (noticing North's ♣10 dropping) and then finesse the ♣9 – not at all obvious. In fact, it comes down to a guess. [Actually, a good strategy after losing to the ♦K is to bang out all your winners in hearts and spades before touching the clubs. It may be that a player holding ♣Jxxx will carelessly discard one, not realising what's coming!]
In Box & Bath
Given the foregoing, you won't be surprised to learn that in Box, all the pairs in spades made at least 12 tricks, whereas the only pair in 6NT went one off.
And it wasn't much different in Bath: all the pairs in 6♠ made 12 tricks, but only ONE of the five pairs in 6NT made their contract. It's just one of those hands!