Play or Defend?

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

The South hand was given to me as a "pure bidding problem", but this turned out to be a very interesting play hand.  At IMPs, would you overcall after 1♦ on your right?  Does it matter whether partner is a passed hand or not, or what the colors are?

FWIW, I think I would basically always overcall.  LHO makes a negative double, and you wind up in 4♥.

Anyway, say you receive the lead of the stiff ♦K.  RHO is 4=2=5=2 with ♠K and a club honor.   Would you rather play or defend?

Here's one way to make on a guard squeeze with a delayed duck element:  they play a trump at trick 2, you win in dummy, play another diamond, they play another trump.  Now ruff a spade, ruff a diamond, ruff a spade, draw the last trump (pitching a spade) to come down to:

♠	A Q
♥
♦
♣	K 10 7
♠
♥
♦	8 7
♣	A 9 4

RHO must keep 2 spades or the queen is good.  If he bares his club honor, his partner is exposed to a finesse, so he must be down to one diamond.  Duck a diamond (the 8, of course) and you have the rest.

Since you're out of trumps, the ♠A is a key card:  you need to hold that to keep control of the suit lest RHO come down to one diamond but be able to cash the SK when thrown in.

You also can't rectify the count in any way since every card in dummy is busy.

I have not checked with deep finesse, but I believe the defense can break this up.  How?  Answer below...

The hint is in the position requirements I pointed out.  One approach is to attack the ♠A:  after winning trick one, LHO can lead a spade.  You play *low* and ruff, and play a 2nd diamond.  If RHO wins this, there's not much he can do except play a red card which puts declarer in control of reaching the desired end position.  But, what if LHO ruffs the 2nd diamond to lead another spade?  Not good enough:  declarer can ruff in hand, ruff a diamond, and overtake a trump to get back to hand and play the last trump.

So that fails.  What about rectifying the count for declarer?  By playing trumps twice, the defense can eliminate dummy's trump winners. Now when declarer goes to ruff a diamond, LHO can ruff in front of dummy for the defense's third trick.  This breaks up the squeeze position above:  declarer can still arrange to ruff a diamond but then dummy is squeezed before RHO.

However, it looks like declarer has another resource:  LHO can't break the club suit and so must play a spade when in with his last trump.  Declarer ruffs that, ruffs a diamond, ruffs a 3rd spade and now dummy is good.

But why can't LHO break the club suit?  Declarer had to pitch one on the ruffed 3rd diamond, so in fact LHO could break clubs, and declarer is an entry shy.

Maybe declarer can counter this by arranging to ruff 2 spades before playing the 3rd diamond?  Now the defense declines to ruff, and declarer has only the ♣A as reentry.  But, that card is also essential to the squeeze position as it gives force to the delayed duck menace.

So, actually, in the end I think the defense can survive with an unusual ruff in front of dummy to squeeze  dummy play. Read more!

GIB shows how it's done

BBO's robot bridge player, GIB, did nicely on this hand:

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

After an uncontested auction to 3N, West led a top spade and cashed 2 more (heart shakes), then switched to a diamond. Next declarer played ♣K which was ducked.

The hand is virtually double-dummy, so go ahead and try it that way.

It looks like you have enough tricks, but you're a bit shy of entries. Say you cross to ♦Q to cash ♠J, what are you going to pitch? If you pitch a heart or club and then lead some club, East will hop up and stick you in your hand in the suit you just pitched.

The answer is to cash both diamonds, ending in dummy, and only then ♠J. Now East is squeezed first and must unguard a secondary honor, setting up a trick for you. Now pitch the other menace and set up your top club. For example, if East pitches a heart, your jack will be good so pitch a low club and lead a club.

It seem the defense could have broken this up by playing a 4th spade earlier.  That does break up the squeeze, but instead gives you an extra entry which is just as good. Read more!

Progressive Triple Squeeze

I was throwing some cards around on BBO and almost without realizing it executed a progressive triple squeeze:

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

I received a ♠4 lead after an uncontested auction to 2NT. I allowed East to win, and he proceeded to lead a low club and the defense cashed 3 clubs as West pitched a heart and dummy a diamond.

Next, a spade was led. I won this in dummy and played ♥J, covered and won. What does West do on the ♣10?

In practice, he pitched a spade, giving me an extra trick in that suit. Now ♠A, ♦AK, ♠8 subjects him to a subsequent red suit squeeze.

Pitching from either red suit would have given up 2 tricks immediately, though neither 2-trick threat was necessary.  After a diamond pitch, play the same way except cash one good diamond for a major suit squeeze.  After a heart pitch, the extra heart winner inflicts a diamond-spade squeeze. Read more!

Test Your Play

From a KO match

♠	5
♥	A Q 10 8 6 2
♦	10 5 2
♣	K 5 3
♠	A J 7 2
♥	K J
♦	K J 8
♣	J 10 6 2

South	West	North	East
			1 ♠
Pass	1 NT	2 ♥	3 ♦
3 NT	All Pass

♦4 led, RHO plays the Ace and another diamond. Say you try the Jack and it loses to the Queen, a 3rd diamond coming back. Now what? Hearts are not 5-0.

Answer below...



RHO has apparently bid a bit crazily, and must have the ♠KQ and the ♣A, and probably the ♣Q. So, run hearts as RHO pitches 3 low spades and 2 low clubs to get to this 4 card ending:

♠	5
♥
♦
♣	K 5 3
♠	A J
♥
♦
♣	J 10

Now play a low club from dummy. RHO can win his Ace and cash a diamond, then you have the rest. A delayed-duck squeeze.

The only way you might even go wrong is if declarer is 6142 and pitches a diamond and a club and 3 spades. You might guess to throw him in with a spade hoping to score ♣K, but will be disappointed.

Read more!

Rosenblum trump compound

[Andy]  It's my turn to blog on Franco's favorite subject.  The following is what will most likely be the most famous hand from the Rosenblum final.  (It was described in the NY Times today also, although I didn't see it online there yet.)

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

Zia got to 6♥ and received the ♠Q lead.  He found an elegant line, cashing his winners and taking 3 ruffs in his hand, then exiting with his last club.  In the end position he could claim regardless of the location of the ♥Q.

Moss and Gitelman did one better, though, arriving in 7♥.  I'm not sure what happened, unless Gitelman intentionally bid a grand on a blackwood auction in hopes that the opening lead would reveal the trump Q.  (This is a somewhat well-known trick, but definitely pretty gutsy in the last quarter of a world championship final that you are winning!)  Anyway, Rodwell did lead a trump, and Moss won the trump A, played trump to K, spade to K, drew the last trump, ruffed the third round of diamonds, played the second to last trump, unblocked clubs, and played the last trump to achieve a double squeeze (spades being the double threat suit).

That was very well done.  Let's take a look at the hand from a theoretical point of view.

With a reasonable number of entries, compound squeeze principles suggest that the contract should be makeable if one positional threat can be found.  It seems natural to hope that suit is diamonds, since declarer can isolate it, and the club threat needs to be in his hand.  Moss' line probably would not have worked had Rodwell held something like ♠J x x  ♥x x  ♦Q x x x x ♣ Q 10 x.  Rodwell would probably unguard spades and keep clubs in that layout, and Moss would not have the timing to unblock the ♠A to achieve a double squeeze around clubs.  (This is necessary since the extra spade winner gives Rodwell an idle card.)

So to achieve full compound generality, declarer appears to need to preserve the ♠K in his hand.  Perhaps declarer could take the diamond ruff before drawing the last trump.  This would leave two entries in both black suits and guarantee a working compound position as long as Rodwell held at least 4 diamonds.  Of course, it might lose if diamonds were 6-1 and RHO could ruff.  It might also lose if LHO overruffs in a position where there was just a minor suit squeeze against RHO the whole time.

An intriguing variant is to start the way Moss did, but play the 4th trump before taking the diamond ruff.  I think that also guarantees the ability to make the contract any time LHO has at least 4 diamonds.  The triple squeeze part of the compound is achieved at that point, since there is a ruff-out threat in diamonds.  Then, if LHO unguards spades at that point and declarer can read it, he can unblock the ♠A before taking the diamond ruff.  If LHO guards spades then the play continues as it actually did at the table.  Cool! Read more!

Another Compound

Dlr E
Vul NS
IMPs

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

West	North	East	South
		3♣	3NT
5♣	6♣	Pass	7NT
All Pass

♣3 led. RHO puts up the Jack. How do you play?

FWIW, RHO is an honest customer, LHO not so much. You can confirm this by playing another club.

My line and further analysis is below.



I tested one more club and LHO pitched ♠4 (I pitched ♠3 from dummy). Then 4 rounds of hearts, LHO following up the line, while RHO pitched ♣7, ♠5, then ♦4.

There's definitely a squeeze available at this point, but I still haven't committed to which one to play for. ♠K drew the Jack from RHO and 6 from LHO. Now I can afford another club before making up my mind: LHO pitched ♠9 while RHO followed with the 5. This is the ending:


 

	♠ A 8
	♥
	♦ K 7 6
	♣
	♠ 2
	♥
	♦ A J
	♣ 10 4

RHO is down to a club stopper and 3 pointed cards. If he started with 4 spades (and so still has that suit stopped), LHO made a very tricky pitch from 3=4=5=1 at trick 2 (and again on the last trick). Not to mention that the aggressive 3♣ opening seems much more likely with 4 diamonds than 4 spades. So, I played a spade to the Ace, and when RHO showed out I claimed: he must pitch his diamond guard here, then ♦A, ♣10 squeezes LHO in diamonds and spades.

If I had thought that RHO guarded spades but not diamonds, then ♦K, ♦A, ♣10 would effect a similar squeeze.

Technically this was just a double squeeze (LHO guards spades, RHO guards clubs, both guard diamonds), but if RHO had started 3=1=3=6 it would have been a true compound (a Type-R Unrestricted).

How about the defense?

East is going to need to make 2 pitches on the hearts, and then declarer is going to need to guess which of the pointed suits East still guards. If, as on the actual hand, East pitches one from each suit, he'd better not have started 3=3 or declarer cannot go wrong. On the other hand, even though East has had to make 2 pitches, always pitching one from each reveals nothing about which suit started longer. If West also pitches one from each suit (he has to make 2 pitches on clubs), declarer faces a straight guess (ignoring the auction), even though this is (or at least looks like) an unrestricted compound.

In compensation, if East did start 3=3, he must pitch 2 from a single suit, and declarer will almost always go right by playing that suit to now be unguarded. When East is actually pitching 2 from a 5 card suit (which he should do instead of 1 from each), declarer should normally go wrong (3-3 vs 5-1 is 25:3 a priori, though knowing an opponent's preempting style might be enough to overcome that).

I guess when the layout is such that it's not a true compound, just a double, that the position-tightening does not actually put anyone under pressure and so it makes sense that proper discarding reveals virtually nothing. There's always a double squeeze present, but it's more or less a toss up as to which to play for if both defenders are perfect. In contrast, when it is a true compound, East is squeezed twice and his discards are much more revealing, making it around 80% that declarer gets it right even against perfect defenders.

Obviously in practice a psuedo-squeeze is much more likely than this layout and West should be minimizing the chance of screwing that up.

Some minor technical points:

1. I should not have played a club at trick 2. RHO might not appreciate what is going on and if he pitches 2 clubs I'm spared any guess.

2. If I do play a club, I might as well pitch a heart. LHO might have trouble pitching from a 4 card holding in diamonds or spades. Also, I might as well play a 3rd (but not a 4th!). This gets more information from LHO early, without really helping RHO much if at all.

3. When crossing back to hand, I should probably use ♦A in case the ♦Q has been bared.

Finally, the ♦J was not strictly necessary, but it does help slightly in constraining the defense. Earlier I suggested that LHO pitching a spade early (and another later) from 3=4=5=1 would be tricky. This follows the general "principle" (technically this principle is false, but that's another post) of not waiting to the last possible moment to release a guard if you're squeeze. Since West is going to be squeezed in diamonds and spades later in the hand, if he anticipates this he has a good chance of leading declarer astray by pitching from his shorter suit early. However, thanks to the ♦J, he actually can't get away with pitching 2 diamonds (he started with Qxx). At double dummy the clash menace is irrelevant, but at single dummy it puts additional constraints on the defense and may make reading the position slightly easier.




The BBO record is here.

Read more!

Finesse played as a suicide compound

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

West	North	East	South
1♦	1NT	Pass	2♣
Pass	2♦	Pass	3NT
All Pass

♥J led. I ran this to my ace and crossed to dummy with another heart to lead a diamond. The Q was allowed to hold, then I exited a diamond. When West ran diamonds, East had to pitch 2 more black cards in this ending:

	♠ A 10 3
	♥
	♦
	♣ A 9 8
♠ Q 9 2		♠ ? ? ?
♥		♥ 10 9
♦		♦
♣ Q 10 2		♣ ? ? ?
	♠ K 8
	♥ Q 7
	♦
	♣ K 7

East must unguard a black suit. Win West's continuation with a king in dummy, then cross in the suit East doesn't guard and back to dummy's remaining K. One of these tricks will squeeze East again in the other black suit and hearts, then ♥Q will squeeze West in the black suits.

As shown, West could defeat this by exiting without cashing all diamonds. In practice, though, I held ♠J (you did notice the very light 1NT overcall, right?) and could always fall back on that finesse.

The BBO record is here.

Read more!