Bridge: how do you play this?

July 22, 2008 at 11:23 pm 8 comments

I keep getting these curly ones in my Inbox. It’s no way to wake up in the morning.

AKJ10xx
10xx
9xx
9
Box
Qxx
AKx
KQ7x
QJx

Contract: 4 by South after a 1NT opening and a transfer. Opponents are silent throughout.
Opening lead: trump

How do you play?

Answer When the hand was given to me the question was is there a difference between playing a club first and a diamond first – the play taken at the table.

AKJ10xx
10xx
9xx
9
xx Box xx
Jxxx Qxx
AJ108 xx
10xx AKxxxx
Qxx
AKx
KQ7x
QJx

The issue is that it is critical to play a club first if the diamond ace is wrong and diamonds don’t break. If that is the layout you need to attack clubs while you still have all your red suit stoppers. But if you play a club up and it is won by West, a heart shift will see you go down with diamonds 3-3.

The declarer who gave me this hand was Victorian David Beckett who tried a diamond at trick two. I expect it is true that assuming perfect defence 3-3 diamonds is a better chance than both clubs onside. Around 36% vs 25%. But presumably, even in a strong game, we have to factor in RHO rising with the ace of clubs (when he does not hold the king) some of the time. And if the first round of clubs is won on your left, it won’t necessarily be easy to shift to a heart, especially since West’s been left with a ‘safe’ spade exit. I think it is fair to say that these incalculable possibilities combined with, as has been pointed out, some squeeze chances, will make the club play attractive, as indeed, I understand, happened at the other table.

Interestingly, although everybody who first responded to this problem did so after seeing all the hands and all played a club, those who have seen only 2 hands have all played on diamonds. I make this point because one statistician/strong declarer said to me that at the table he thought he would have played a diamond up, as did Beckett and as did I when presented it as a problem. I am told that when given it as a single-dummy problem Tony Nunn also tried the diamond.

For those who like mathematical calculations, Victorian player Robby Van Riel has supplied this:

So the basic probabilities are 62.5% for playing on clubs and an unadjusted 67.8% for playing on diamonds; on paper, the diamond play is right. RHO will have CA but not CK 25% of the time. The more likely RHO is to rise with CA in this instance the better the chances for the club play; the break-even point is when you think RHO’ll rise about 20% of the time. I’d say this plus LHO’s potential difficulty in switching to hearts put the club play in front.

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Entry filed under: declarer play. Tags: , , , .

Bidding problems. What do you do with these? Bridge: what line do you take?

8 Comments Add your own

  • 1. Ben Thompson  |  July 31, 2008 at 1:27 am

    If the club loses to LHO, he has to:
    (a) be able to find the heart switch (suppose you hold HQ – do you really want to open up hearts when declarer might have AJx … and going passive leads to a gentle one off)
    (b) have a holding where switching hearts works (eg if he has HQJ we have excellent chances even if DA is offside; if we have the secret H8 .. or better yet the 9 .. the suit may be frozen with weaker heart holdings with LHO)

    Against double dummy defenders, I calculate that playing diamonds first is about 6% better. If you have the H9, playing clubs first is about 6% better. If you have H8, playing clubs is about 1% better.

    If you think that LHO won’t shift to a heart with the Q (he can with QJ, but it doesn’t help much) but that the defenders are otherwise double dummy, playing diamonds wins by about 2%. So how likely is RHO to hop with the CA? Anything more than about 1 time in 7 and playing clubs wins.

    Reply
  • 2. Bill Jacobs  |  July 27, 2008 at 10:34 am

    Some limited experience tells me that I don’t much like the idea of having Garozzo on both my left and right.

    As for the problem itself, I think it’s a fine question about who is on your right. In particular, how likely is my RHO to fly ace with A (but not king) of clubs? That seems to me to be the key question.

    And I don’t agree with Robbie’s maths. He keeps waffling on about a 3-2 spade break, but it seems to me that there are only 4 outstanding spades.

    Against a computer who can see all four hands, a diamond looks correct. Against humans, you have to decide how Garozzo-like your opponents are.

    Reply
  • 3. sartaj  |  July 24, 2008 at 3:16 am

    My thoughts…

    Playing a club gives up on our genuine chance of diamonds 3/3 or J10/108/J8.

    When my LHO leads a trump, the chances of both club honors onside are rather low.

    Giving a play problem while showing all four hands is no good.

    Love the sneaky aspect of running the 9 of clubs.

    Rodwell’s thoughts on playing as declarer : “I try to play as if i had Garozzo on my left and Garozzo on my right.”

    In good old Oz, a club is clear. It works …..

    On a different planet….. ?

    Reply
  • 4. cathychua  |  July 24, 2008 at 3:11 am

    Thanks Rob for providing the maths which I have added to the bottom of the main post.

    Reply
  • 5. Simon  |  July 23, 2008 at 4:52 am

    Win in dummy and lead a club – the best technical line and psychological attack…

    Reply
  • 6. Rob van Riel  |  July 23, 2008 at 4:30 am

    I’m with Ben too. To the “puh-lenty” of chances I’d add diamonds 3-3 or J10/J8/108 doubleton. Michael’s “running the 9C” seems to give up unnecessarily on some legitimate positions (like the one in the diagram).

    Reply
  • 7. Michael Ware  |  July 23, 2008 at 2:49 am

    I agree with Ben but would have worded the club play as “running the 9C” – it would be great defence by East to play low.

    Reply
  • 8. Ben Thompson  |  July 23, 2008 at 12:00 am

    Win SA and lead a club. Later, run a big club ditching a diamond. If the club had lost to lefty, still puh-lenty of chances (DA on side, various squeezes).

    Reply

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