Thursday, July 8, 2010

Play the card you're known to hold

This was from the USBC round of 16, and was reported in the daily bulletin.

If you like, cover up North-South and plan the play on the auction and lead and shift shown below.

Board 82
Vul N/S

♠ A 8 7 6

7 6 4

Q 4

♣ 5 4 3 2
♠ 2
♠ K 5 4
9 8 3 2
A Q J 5
A 10 8 2
9 7 6 5
♣ A Q 9 7
♣ J 10

♠ Q J 10 9 3

K 10

K J 3

♣ K 8 6


DoublePass4All Pass

3♠ was a mixed raise

Opening lead: ♠J (Rusinow)

North won ♠A and switched to the Q. That was a mean play!

More below...

Let's say you duck this, South playing the 3. North continues 4 to South's Jack and you win. Now what?

I figured North probably had no Kings, so decided to hope South had roughly his actual hand: heart to the Ace, then 4 rounds of clubs to shake 2 diamonds. 

Of course, this play might have been harder to find if I didn't know who held the
J. If North could still hold the 3rd diamond, then it might just be right to draw trumps, even if the finesse loses there'll still be time to get all your tricks without losing a 2nd diamond trick.

I would still basically know South had all the Kings (if North is presumed to hold QJx in diamonds), though, and might choose to play
A and 2 or 3 rounds of clubs (depending when they cover) before committing to what to do. I think it's a virtual guess: The non-King red cards split 3-1 in one suit and 2-2 in the other and you need to know which way.  The 10 falling under the Ace might be suspicious, and a harder false card to find than K, so maybe I'd still get it right. 

Of course, the K could plausibly have been on the whole time, maybe this was too fancy.

The other table stopped short of game, so this won 6 IMPs.


  1. When I saw the title, was expecting to read about board 90 from the same segment. That was another slightly unfamiliar application of the "known to hold" principle. Declarer had Axx/QTxx in the key suit...after he played A, low to T and J, I played one back to Franco's K. If declarer had dropped the Q, Franco would have had some doubt about who had the 13th, which was a crucial issue (though it turns out the context should tell him what's going on, assuming declarer isn't nuts.) This was the last board so North was quick to point out his partner's failure to falsecard. Fortunately for South's sanity it turned out the last board didn't swing the match, though it was close.

  2. For people who play 3S as a mixed raise, what would 3D be in this auction?

  3. JW: Maybe I was about to post board 90! Actually, wasn't planning to.

    MM: I don't know how they played 3D.