Jeff Lehman

Cooperative doubles after 1NT openings ala Phillip Martin

One of my favorite bridge conventions is cooperative doubles after we open 1NT and the opponents intervene.  The convention is explained by Phillip Martin at

To show the richness of the convention, I am going to present an illustration.  Just as the convention is a steal from Phillip Martin’s website, the illustrated hand is a steal from BridgeWinners website.  There, Kit Woolsey was presenting another of his fascinating “over the shoulder” analyses of a hand he played in the Rosenblum Cup.  I have slightly modified the hand presented by Woolsey to make the opening bid of 1NT consistent with the 12-14 range adopted by most of my partnerships, rather than the 10-12 range used by Woolsey and his partner on the hand.  If you should use 15-17 as the range for your 1NT opening, feel free to further modify the hand.  The actual ranges you use do not matter: if your range for opening 1NT is 3 HCP higher than my range, then your range for responder’s cooperative double will be 3 HCP lower than my range.  What is important is not the relevant ranges but the distributional inferences that can permit the opening side to compete effectively when their 1NT opening is met with interference.

Before presenting the illustrated hand to describe how the cooperative doubles apply, allow me to first state that a partnership has many choices how to define a double of an overcall of their 1NT opening.  Many partnerships use a double as penalty and many other partnerships use a double as takeout.  I can’t definitively say that their use of the double is worse than my using the double as cooperative.  All I can say is that I prefer the cooperative double use.

The primary purpose of the cooperative double is to penalize the opponents when they have interfered with our 1NT opening and our side has: (1) the balance of power, meaning usually 22-25 HCPs; and (2) sufficient length in the trump suit of the opponents — sort of a Total Tricks concept, but on defense –, meaning six or more combined trumps if the opponents are in a two-level contract or five or more combined trumps if the opponents are in a three-level suit contract.  Failing the second of those two conditions, meaning we have the balance of power but insufficient combined length in the trump suit of the opponents, we seek the secondary purpose of the cooperative double, to compete effectively for a partial.

OK.  Enough talk; let’s show some cards:


Vul: West





















West opens 1NT, showing 12-14.  North overcalls 2, in the instant case showing the major suits.

East has the prototypical hand for the cooperative double: 10-11 HCP, doubleton in the suit of the overcall, at least three card support for each suit other than the suit of the overcall.  One of the interesting aspects of the convention is that the meaning of East’s double is not altered by the meaning of North’s 2 overcall.  Whether 2 shows the majors (as here), or clubs, or a two-suiter with or without clubs, or a one-suiter not necessarily clubs … that does not matter.  In all of those cases the cooperative double by East shows a doubleton in the suit overcalled.  (A few other hand types of East also call for a cooperative double, as discussed in Martin’s article, but here I will focus on the prototype shown here and leave the discussion of the other types and the follow ups to those other types to Martin’s article.)

What East is hoping will happen is that the strength and distributional information provided by East’s cooperative double will enable the partnership to penalize the opponents.

Let’s see what might happen next.

Let’s first assume that South bids 2, asking, per the N-S agreements, for his partner to bid his better major.

West will double 2.  Knowing — because of East’s cooperative double of 2 — both that his partnership has the balance of power, and that East has at least three diamonds, West can make a penalty double of 2.  If, on the other hand, West had only a doubleton diamond (which means that the combined diamond length of EW could be as few as five), he would pass 2.

North runs to 2.  If East had four hearts, East would double 2 for penalty.  Combined with the minimum of two hearts expected of West for his 1NT opening bid, East would know that the EW partnership has at least six combined trumps, enough to penalize a 2 contract.  However, in this case East was dealt only three hearts, the minimum number he promised when he made his cooperative double on the previous round.  Hence, East must pass 2and hope that West has at least three hearts and can make a penalty double.

Alas, when 2 is passed around to West, West can see that the opponents have found a successful escape.  West has only two hearts and his partner has only three hearts; not enough combined heart length to double the opponents.  Given that EW still has the balance of power on the hand, however, West can hardly afford to pass out 2.  Instead he must compete for the partial.

How might West compete for the partial?  Well, if West owned four spades, he would bid 2.  East has promised at least three spades, maybe more, from East’s first round cooperative double of 2 and so 2 should have play.  However, in the instant case, West has only two spades and so a 2 call is out of the question.  What does West know about East’s distribution?  He knows that East has a doubleton club (from the initial cooperative double of 2 made by East).  He also knows that East has exactly three hearts (three or more hearts were promised by the cooperative double, and East has denied as many as four hearts by having failed to make a penalty double of 2).  Hence, West knows that East has eight cards in the pointed suits.  These eight pointed suit cards might be divided 4-4 or 5-3 either direction.

If West’s distribution were 2=2=5=4, West could safely bid 3 here.  He would know that East has at least three diamonds and so the fit for a 3 contract should be acceptable.  However, West’s actual distribution is not 2=2=5=4 but is 2=2=4=5.  Now a 3 call risks landing the partnership in a seven card fit at the three level; that would surely not be acceptable.  Accordingly, West’s actual call in passout seat is 2NT, a scramble call.

To summarize the auction to date:

West North East South
1NT (12-14) 2(showing majors) Dbl (10-11 HCP, doubleton club, at least three cards in each other suit) 2(asks for better major)
Dbl (3+ diamonds) 2 (better major) Pass (denying 4+ hearts) P
2NT (scramble)

Now let’s move to East’s seat and explore the distributional inferences East has available about West’s hand.  First, East knows that West has at least three diamonds (because West made a penalty double of South’s 2 call).  Second, East knows that West has exactly two hearts (because West failed to make a penalty double of 2).  Third, East knows that West has fewer than four spades (because West failed to balance with 2 call).  Fourth, East knows that West has fewer than five diamonds (because West failed to balance with a 3 call).  The possible distributions for West are 3=2=3=5 or 3=2=4=4 or the actual 2=2=4=5.  To avoid the risk of playing 3 on the first of the three possible distributions, where the partnership has only seven combined diamonds, East will pass West’s 2NT call.

And, lo and behold, 2NT is probably the best place for EW.  Even if, on a different allocation of the high cards, NS could run the first five heart tricks against 2NT, chances are strong that EW can claim the final eight tricks.

Let’s go back to an earlier stage in the auction.  Let’s assume that instead of bidding 2 at his first turn to ask for North’s better major, South had passed 2X.  Of course, West would pass 2X, too.  But North would rescue his partnership by calling 2.  East would pass 2.  As before, the parlay of East’s first round cooperative double of 2 and his second round pass of 2 would show exactly three hearts.  As in the actual auction, West would balance with 2NT.  And again, East has available to him enough distributional inferences about West’s hand to pass 2NT.

Cooperative doubles after the opponents have interfered with our opening 1NT are not bullet-proof.  The emphasis by the opening side on showing distribution and overall strength overlooks the location of honor cards.  When honor cards of the opening side are concentrated in their short suits and not their long suits the offensive potential of the hand will be overstated.  Nonetheless, I have found cooperative doubles to be among the more useful conventions I have adopted.  I hope this post, combined with a reading of Martin’s article, will help demonstrate why cooperative doubles can be so useful.  Martin also explains the use of a cooperative double by the opening 1NT bidder. I like that use, too, although it can backfire more frequently than the use of cooperative doubles by responder.

1 Comment

RobinMay 3rd, 2011 at 7:30 pm

Now that I see this written up, I believe I am in favor of trying it. Although I’ve been playing these doubles as negative, there is always that risk of passing for penalties and finding responder with a void (opener of course always has two). This scheme seems to deal with that issue quite nicely. I particularly like the rule: “Until responder has shown values, a double by either player is for takeout”.

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