[aleatory]

(P) - 1♣ - (1♥) - 1♠
(2♥) - Dbl

Does the double show 3 spades?
If not, what is it?
If so, what's the difference between double and 2♠?

[aguahombre]

Did 1 ♠ already show 5?

[helene_t]

This is commonly played as a support double, in which case 2♠ shows 4.

But if 1♠ shows five, it can probably be put to better use. I would like to double with two spades and six clubs, or with five clubs and 4 diamonds.

[aguahombre]

helene_t, on 2014-February-20, 04:15, said:

But if 1♠ shows five, it can probably be put to better use. I would like to double with two spades and six clubs, or with five clubs and 4 diamonds.

Even though our 1S only shows 4+, we suck it up and use Helene's scheme anyway.

2S..might only be 3 if short in hearts (If Opener has 3 hearts, we can hope Partner will keep it open holding 5 spades.)
X="good/bad" style merely competitive in clubs with 2 Spades.
2NT=good/bad competitive in clubs, spade shortness --
3C=the real goods.
Sometimes we even Pass.

[Zelandakh]

aguahombre, on 2014-February-20, 05:01, said:

Sometimes we even Pass.

Heresy!

[trevahound]

aguahombre, on 2014-February-20, 05:01, said:

Even though our 1S only shows 4+, we suck it up and use Helene's scheme anyway.

2S..might only be 3 if short in hearts (If Opener has 3 hearts, we can hope Partner will keep it open holding 5 spades.)
X="good/bad" style merely competitive in clubs with 2 Spades.
2NT=good/bad competitive in clubs, spade shortness --
3C=the real goods.
Sometimes we even Pass.

I tried passing once. While it worked, it made me feel dirty.

[kenberg]

I think that it is useful to play it as support, with the immediate raise showing 4. It is highly likely that the opponents will be willing to jack the bidding to 3♥, and knowing about that fourth spade, or the lack of it, might help us decide what to do about that.

[aguahombre]

kenberg, on 2014-February-20, 17:02, said:

I think that it is useful to play it as support, with the immediate raise showing 4. It is highly likely that the opponents will be willing to jack the bidding to 3♥, and knowing about that fourth spade, or the lack of it, might help us decide what to do about that.

That is precisely the thinking of the creators and practioners of the Support Double --- and it is good thinking, of course. We just believe in the value of other uses for those doubles. We are in the minority.

[aleatory]

aguahombre, on 2014-February-20, 04:15, said:

Did 1 ♠ already show 5?

Yes 1♠ definitely shows 5+

[kenberg]

aguahombre, on 2014-February-20, 18:02, said:

That is precisely the thinking of the creators and practitioners of the Support Double --- and it is good thinking, of course. We just believe in the value of other uses for those doubles. We are in the minority.

I can see reasons for other views. I have always thought that one of the downsides of the support double is that it can blur the decision to play in a 4-3 fit. With KJx for support and shortness in the opponent's suit, a 4-3 fit might play well With xxx as support and Qxx in the opponent's suit, maybe the 4-3 is not going to go well. Without support doubles I simply raise on three card support with the first holding and decline to do so on the second. Playing support doubles, I make a support double with either holding. This is not always best.

So yes, I can see the point.

[SteveMoe]

Here's an alternative view -
Support doubles apply at the level of 2♥ or below. (Over 2♠ we would be forcing partner to the 3-level with only a 7-card fit - an ANTI-LAW decision).
When responder shows 5 or more cards, opener can freely raise on 3 pieces. e.g. 1♣-(1♥)-1♠-(2♥), 1♦-(1♠)-2♥-(2♠)
When responder only promises 4, but might have 5 or more, then the double is Support.1♣-(1♦)-1M-(2♦) a double is support as 1M can be only 4 cards. Also 1♦-(1♠)-Double-(2♣), now opener's double is Support for ♥ implied by the negative double.

So if opener can raise on 3 card support, what does the double mean?
1) it should show at most a tolerance and likely a poor fit for responder's suit.
2) it should show 3 cards in opponent's suit (H10x or better preferred).
3) it denies a biddable suit for the 3-level (i.e. not strong 5-5, not 6+).
4) it shows extra strength for previous bidding, enough to suggest penalties if partner has the right hand (strength or trumps suggesting opponents are in a 7-card fit).

Examples for your given auction might be: ♠xx ♥KJx ♦KQx ♣AJ10xx (maximum balanced hand if playing 15-17 HCP 1N opening bids. Playing weak NT this double implies a 15-17 HCP hand.) or perhaps ♠x ♥KJx ♦KQJx ♣AKxxx or similar heavy unbalanced hands.
These doubles are Optional Takeout or DSIP (Do something intelligent, partner) and are more frequent and lucrative than (ancient) penalty doubles: ♠xx ♥KQ10x ♦A ♣AK10xxx - when opponents bid and raise it's unlikely we'll hold 4 top cards in their 8-9+ card fit.
The idea is to increase the frequency we can manage +200 or 300 or more on what's otherwise a part score hand.

[fromageGB]

aleatory, on 2014-February-20, 18:02, said:

Yes 1♠ definitely shows 5+

In that case I can't see why a hand with 3 spades would not bid 2♠, and have the double as showing tolerance (2 card support) and playable elsewhere (as helene_t wrote).

I would still call this a support X, but rather than the definition being "always 3 cards", it is "one fewer that would be normally be expected to support directly" and it can also apply at the 3 level.

[Zelandakh]

In a weak NT context this double is typically a strong NT; in a strong NT context my choice would be that it shows something like ♠Hx, which is not only useful in terms of finding the best fit but also on defence.