[hatchett]

Playing IMPS against unknown opposition you hold

♠QJ83
♥AQ73
♦T2
♣KJ4

They are playing a lightish 2/1 response style and they bid


1♠ 2♣
2♦ 2NT
3♠ 4♠


They are unsure whether 3♠ is forcing or shows extras, 2NT being a non forcing invite. The opening bidder is on your left.

Do you double?

[HeartA]

Double? not my style.

[Free]

Double??? Why???

[bid_em_up]

Although I certainly have reasonable expectations of beating 4♠, a double in this position (underneath declarer) may just let him find the winning line of play (or at the very least, go down less than if left to his own devices), so no, I dont double.

If I was behind him, I would be slightly more inclined to do so, but not by much.

[neilkaz]

When you double in a non competitive auction at Imps it is good to have a reasonable expectation of beating them 2 tricks. Here you have a bad split surprise for declarer and you may be favorite to set it 1, two is unlikely. I don't see where doubling has positive expectancy here as it may also aid declarer in play since your tenaces will be more easily finessed and he'll be aware of a great possibilty of a poor trump split.

[hatchett]

Quote

Double??? Why???

Well I was playing with a very good player who found a double for +500, 3 off.
Dummy had the expected AQ♣ and K♥ and I had some diamond honors. Declarer didn't have the entries to pick up ♠ despite knowing about the split.

[Codo]

I had never thought to play you for some diamond honours. Wyh on earth should you have them?
And if Dummy holds them, he not just has one or two more tricks in Diamonds but he has enough entrees to get the spades right too.

So the X was based on the assumption, that your opps did not know, what they are doing and this idea ws right and rewarded.

[mikeh]

I believe I am correct in suggesting that most competent players would intend the 3♠ bid as forcing... with a weak 6=4, if 2♣ was not GF, one should bid 2♠.

So when you write that 'they' did not know if 3♠ showed extras, I assume you mean 'responder' could not tell you that.

In that situation, doubling appears insane... declarer, if competent, has a strong 6=4 and you have just telegraphed the trump layout. And why, why are your ♣ cards any use on an auction in which declarer will hold a stiff more often than any other length?

Now, if declarer told you that he didn't know what he was doing, maybe, just maybe, the double is worth a shot... on general principles, any player who does not know what this common sequence shows is probably not a good technician anyway

The fact that the double worked does not make it a good bid.

If declarer had the hand he promised, he might have AK10xxx xx AKJx x opposite xx Kxx Qxx AQxxx and there would be a good chance of beating the game until the double.