Thursday, April 17, 2014

The cooperative double

I've written on this subject many times before here in this blog, see nine (currently) articles as well perhaps as some others of the articles answering to the label double.

A lot of the foregoing has concentrated on the rules and triggers for penalty doubles. That's to say what a cooperative double is not. What I want to do here is to try to explain simply and succinctly what it is and why you would use it.

A cooperative double is just another kind of double from which you are ready for partner to take out. In this sense it is no different than takeout, negative, responsive, support, snapdragon and maybe a few other types. What distinguishes a cooperative double from these other doubles is that the expectation of a takeout drops to somewhere around the 50% mark. You will have tried to find a fit with one or two suits mentioned already and so far you've been unsuccessful. The cooperative double is one last try. You invoke it because you believe you have as much right to declare this hand as the opponents, maybe more. But you fully expect that, about half the time, partner will leave your double in. You won't be surprised, as you might be when partner passes a takeout double. Instead, you'll get your defensive shoes on and prepare to take all your tricks to defeat the opponents' contract.

So, let's get a little more specific. First of all, what level do we generally find a cooperative double on? The most common is probably the three-level, but it can be found at almost any level, except the first which is more the realm of the above mentioned cousins.

Second, what about strength? There are two possibilities: the doubler himself has extras, perhaps a queen over minimum (which would normally give the doubler's side at least half the points in the deck), or the partnership taken together is known to "own" the hand (at least about 22 hcp).

Finally, and this is the key point, what sort of hand does the cooperative doubler have? Simply put, he will be one card short of a bid in each suit that hasn't been claimed by the opponents. Too few cards to support partner, too few to rebid his own suit, too few to mention a new suit (he would typically have five to mention a new suit at the three-level, for example). Let's say doubler has four of his own suit, having implied four, three of partner's suit (he having promised four), and four of another unbid suit. That leaves two in the opponents' suit. In other words, much of the time he will double with a balanced hand holding two cards in their suit. When partner leaves the double in with three or four cards in their suit, she will be counting on about two trumps in the other hand. Occasionally, as the level gets higher and you are more reluctant to introduce a new suit by bidding it directly, you might be reduced to only one card in their suit. Partner will take the auction so far into account when deciding to pull or pass the double. She will only pass when she has no extra distribution of her own beyond what she's already promised (can't rebid her suits and can't support yours) and, hopefully, she will have something usefully placed in the enemy suit.

Furthermore, if there are two unbid suits, doubler should have approximately the same length in each, perhaps one card different (5-4 or even 4-3). But two cards (6-4) is far too much disparity in my opinion. Not only might you end up in a 4-4 fit when you have a 6-3 fit available, not in and of itself a tragedy, but if partner has 3-3 in the unbid suits, you may end up defending a doubled contract despite having a nine-card fit of your own. This is not the time to be defending unless the level is high enough that you expect a substantial penalty (i.e. a sacrifice situation). Of course this applies to negative and responsive doubles too.

Now let's look at things from the other side of the table. Partner has made a cooperative double. Should you take it out or leave it in? If you have one of the distributional features (assets) that partner is looking for, bid it, even if you fancy your chances on defense. Nothing is more demoralizing than doubling the opponents in some part-score and then having it make. Sometimes it is supposed to go down but you need double-dummy defense or even a lucky defense to set it. For this reason, I believe that passing the double should be the last resort, especially at teams. The cooperative double is a way to find our own contracts more than a way of nailing the opposition. Declaring at both tables of a team game can generate a lot of swings in the 4-7 range. And at matchpoints, you will be winning a lot of boards simply by successfully outbidding the opponents. The occasional penalty will be a bonus but it should not become an end in and of itself.

The lower the level, the less willing partner should be to leave the double in and, conversely, the higher the level, the more willing partner should be to pass (but note that doubler may have fewer trumps as the level gets higher as explained above). Doubled and freely-bid suit contracts at the two level are rarely very profitable. The one exception being after an overcall is followed by a reopening double. But even that situation is usually not very profitable at the one-level. And of course, vulnerability should be factored in. Stretching to double the opponents when they aren't vulnerable is not winning bridge, especially if bidding on would give us a decent shot at a vulnerable game.

Note also that the cooperative double is part of a bidding style often called Do Something Intelligent, Partner (DSIP). But I've come to the realization that not only does DSIP suggest a more extreme (looser, more speculative) version of competitive bidding but, with a disciplined cooperative double, partner isn't required to do anything more intelligent than looking to see if he has any undeclared offensive assets and acting accordingly.

The cooperative double can also go by several different names (card-showing, action, etc.). One of the most apposite is Mel Colchamiro's "BOP" double (for balance-of-power). The BOP double is in fact a slightly more conservative version of the cooperative double and well-suited to IMP scoring. In order to use it, the partnership must have the balance of power (not just equal power) and the doubler must be sitting under the hand with most length in the suit.

Experts routinely make use of cooperative doubles below the level of game. For the expert, it is a sharp weapon. However, lesser mortals need to remember that like any other weapon, it can end up being turned against us. So, understanding the benefits and limitations of the method and being disciplined about its use is extremely important. It is easy to get carried away and double without the proper values or while holding a card that may be valuable, offensively, to our side. But, properly used, it will gain you matchpoints and IMPs in the long run.


  1. I held a hand playing on BBO that made me think of you.

    What does the second double show in terms of suits and strength in this auction:
    2D dbl 3D dbl?

    1. This is a standard responsive double and I'd say it would show about 9+ hcp and both majors (no preference), most likely 4423 or 4432 shape. I wouldn't do it, for example, with 5512 shape because now if partner does decide to pass for penalties we will almost certainly be in the wrong contract.
      You might also do it with 3334 shape and something like 11+ hcp but no diamond stopper.