Monday, December 15, 2014

Doubling 3NT for a lead

I've previously talked about various different sorts of lead-directing double. But I couldn't find any article where I had discussed doubling a 3NT contract for a lead. It's uncommon, for sure, but when it comes up, you really need to be on the same page with your partner.

Following the same principle of the Lightner double of slams, there is little reason to double a freely bid 3NT to increase the penalty. The arithmetic just doesn't support it. Suppose that they have bid a silly 3NT, not vulnerable, and you think, based on the auction and your holding in the suits bid on your right, that the contract will go down on partner's normal lead, most hopefully by two tricks. Let's say, for the sake of argument, that the probabilities of various numbers of tricks for declarer are for 6 thru 10: 10%, 40%, 30%, 15%, 5%. At the other table, your teammates are in the more sensible contract of 2NT. The lead and the number of tricks taken are the same at both tables (yes, I know this is a big assumption). The number of IMPs in your favor is expected to be: 9 * 10% + 6 * 40% + 6 * 30% + -9 * 15% + -9 * 5%, which comes to 3.3. This is modestly positive but it might actually go negative if the opponents redouble when they are making, especially if they are vulnerable. And, then there's the very likely eventuality that they will run to a making part-score or, worse, game. And, far worse, the ignominious possibility that your double will tip declarer off to the winning line!

Contrast this with the situation where the opponents are actually going to make (-6 IMPs) on partner's normal lead, but will go down when you tell partner what to lead (+5 IMPs). That's a swing of 11 IMPs. The swing when the opponents are vulnerable would be 16 IMPs.

Unfortunately, you can't lean over to partner and say "lead a club", though you could try coughing (JK). You have to have a general agreement about what lead you want based on the auction.

Here's the scheme that I think makes the most sense and is easiest to remember:
  1. if leader has bid a suit, then lead that suit
  2. else if doubler has bid a suit, then don't lead that suit
  3. else if dummy has bid a suitthen lead that suit
  4. else use your judgment, normally leading your lesser major suit.
I'm also willing to play #2 as "do lead my suit" but it seems to me that partner is probably going to lead my suit anyway. The idea of "don't lead my suit" comes from George Rosenkranz's Tips for Tops. It can often happen that either because doubler had no opportunity to bid two suits or simply because, say, he opened a suit with nothing much in it he thinks that they will go down if you lead something intelligent. It might well be dummy's first bid suit. Let's say that the auction has gone 1♠ (X) p (2) p (3NT) p p X all pass. Your hand is ♠Kx Jx Txxx ♣Jxxxx. Normally you would lead the ♠K. But partner is asking you not to lead a spade. What could his other suit be? Could it be hearts? Double of dummy's 2 call would have been takeout-oriented, not penalty. Declarer has the spades stopped and he has enough tricks in one or both of the minors for his contract. He's relying (inadvisably) on dummy's hearts and/or hoping you will lead a spade. Get that J on the table, therefore.

The reason for the first rule is that partner may be loath to lead away from a holding such as AQT73 after his RHO has bid notrump. But sometimes players will consider J982 a stopper. If partner has the K doubleton, you can take the first five tricks. But if you lead something else, looking for partner's entry, by the time you get to run those spades it may be too late. Of course, you might have been going to lead your suit anyway, lose the first trick to declarer and then wait for partner to get in and lead through. But there are two things that can go wrong with this plan: declarer may be able to hold up long enough to exhaust partner, or partner may have nothing to get in with. This is particularly true when you have opened the bidding or overcalled—the very occasions when partner will want to take the opportunity to tell you the good news.

In any case, this worked out well during the recent 0-5000 Blue Ribbons in Providence, RI. I opened 2D (weak two) with nobody vulnerable. My diamonds were QJTxxx and I had an ace on the side, I think (ACBL "Live" has lost the details of this event already so I can no longer be sure of the whole layout). My RHO ended up in 3NT and partner doubled with Kx. We soon had a top with +500.

In the second part of this blog, we will talk about the most problematic of all calls: double after it goes 1NT pass 3NT.


  1. I'm glad you brought this up because I have a question. LHO dealt and the opponents went 1C-1S-1NT-3C-3NT. I'm sitting there with AKQTx in spades and nothing else. Would you double, allowing the opponents to run to 4C, or do you just keep quiet and hope that partner either guesses right or I get to signal later in the play? I figure partner has to have a trick somewhere.

    1. IMO, you can't worry about pushing them into a makeable 4C. What you cannot permit is for them to make an unmakeable 3NT! So, yes, I would strongly consider doubling for a spade lead and likely set. There's only one minor problem. If declarer has SJx(x) and partner just x (or void), you aren't setting this contract without some tricks from partner. I think I would still double but be prepared to apologize to partner.

    2. Thanks. I wouldn't worry about your caveat too much. If partner is void then the opponents will find their spade fit (!). If declarer has the SJ, it will drop.

  2. What lead does a double call for when our side has bid two suits? Example: 1D 1S(Pard) 2H 3C(me); 3nt pass pass double?

    I think the 1S bidder should lead his own suit (because he would normally lead the club so his pard could lead a spade back through), but I'm not sure what is standard. Your thoughts?

    1. Well, that's the thing. There is no "standard". But as you say, leading clubs would be normal here. So the double says "lead spades (your suit) -- I have a top honor for you over here.

      I published a discussion on BridgeWinners on this but haven't yet got round to creating a poll to ask this question. But I think from the comments so far that spades would be the favorite.

  3. I wrote up an article on this subject, together with some lead polls, on the BridgeWinners site: