Monday, November 21, 2011

Inferences from two-way doubles

Continuing my series on two-way doubles, I want to address some aspects of the call which may not be obvious, at least not until you give it some thought.

In a competitive auction after you've bid/rebid a suit and partner has bid/rebid a suit, and the opponents have "butted in" and perhaps raised with their suit, you have the usual three choices: bid, double or pass.  Let's say you double (this is an example of what Mel Colchamiro calls a "BOP" double).  First of all, you have extras, or you know that the partnership has sufficient values to compete safely (the number of points required depends of course on the level) or we know we have the balance of power (BOP).  Secondly, you are more or less balanced.  If your hand was unbalanced, you would be introducing a new suit, or possibly rebidding your original suit.  Finally, and this is the key point, you should have exactly one fewer cards in partner's suit than you would need to raise.  This is because one of the various things that partner can do in response to the double is to rebid his suit.  So you must have tolerance for that suit.  If partner has bid two suits, you must have tolerance (i.e. one fewer card than you need to raise) for each of his suits.

Let's look at an example: all vulnerable and you deal yourself ♠95 Q3 A76 ♣AKT954.  You are playing a less-than-expert pair.  You open 1♣ and partner responds 1.  RHO now enters with 1♠.  You rebid your clubs, denying three hearts and suggesting good clubs since you could have passed, and LHO ups the ante to 2♠.  Partner is there with 3 which is followed by two passes.  LHO now reckons her hand is worth another bid (3♠).  This is followed by two passes and it's your turn to act.  Obviously, partner has good hearts over there to have been able to bid 3. Yet that bid was "to play", though admittedly there wasn't a lot of room for investigation.  Partner might have stretched to compete or might be just below what he would need to bid (or invite) game [we don't play the good-bad 2NT which might have helped a bit].  What to do?

One of my esteemed colleagues felt that 4 by me was clear cut, with already having denied three hearts by not making a support double earlier.  Certainly I have a key card in partner's suit and prime values outside.  I'm clearly at the top of my range for the bidding so far.  But is 4 necessarily going to make?  Is 3♠ going to make?  Moreover, do these opponents "follow the LAW?" or could they be out on a limb?  I decided against taking unilateral action and therefore doubled.  Since no triggers had occurred (see previous articles, for example DSIP rule summary), this says the following to partner:
  • I can't quite raise your hearts, but I'm close;
  • I have a little bit more than I've promised and/or I feel that this is "our" hand;
  • I don't have sufficient clubs to bid them a third time;
  • I can't bid 3NT;
  • I've got something in diamonds, but nothing biddable;
  • I'm short in spades, most probably I have a doubleton;
Partner infers that my hand must be something like: xx Xx Xxx XXxxxx or xx xx Xxx XXXxxx where X stands for a useful honor.  I should not have xx x Xxxx XXxxxx or xxx x Xxx XXxxxx or xx x Xxx XXxxxxx because while consistent with the bidding so far, those hands would be inconsistent with the double.  It's true that we might be able to make 4 in the first case, or 4♣ in the second, but we shouldn't speculate about a 4-of-a-minor contract.  4♣ or 4 are all well and good if we've already established a fit in the suit and feel that we can safely outbid the opponents.  With those hands (singleton in partner's suit) we should be happy to defend undoubled.

Many of these inferences, including the likelihood of having a doubleton in the enemy suit, stem from the simple fact that each of us holds exactly 13 cards.

On this particular occasion, partner's hand was ♠Q K986542 Q9543 ♣–.  In case you're wondering, 3 was not available to partner over 1♠ because we play fit-showing jumps [I don't think a preemptive 3 would be right with that hand regardless].  The shortness in spades (opposite partner's professed shortness) and the weak, unbalanced nature of the hand strongly suggests declaring.  We might not make 4 (or 4) but if we're lucky they won't double and -100 will beat -140.  If we do go for 200, we can always blame partner in the post mortem (just kidding!).  In practice, 4 does make (as does 4), there being one obvious loser in each suit other than clubs.  Of course, we are not seriously considering 4 since it wouldn't be game and if we are going to go down, we might was well be hung for a sheep as a lamb.

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