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Grand Lady Where is she?

#1 User is offline   lamford 

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Posted 2025-January-27, 17:39

An interesting hand from the 1st EBL Seniors Online

North leads the KD. Over you you.
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#2 User is online   smerriman 

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Posted 2025-January-27, 18:58

Don't have much hope in the expert forum, but might as well throw something out there before Mike posts the real answer..

If North has Q then we make on a squeeze (assuming North must hold Q) as long as we leave clubs to the end.

Or we could try ruffing one low club which makes if Q is in the short hand, but that's not as likely, and if someone has Qxxx I can't see any way past 12 tricks.

Or we could try two top clubs and run the J through South, which works if south has Qxxx or less or North a singleton or doubleton Q, but that's still not as good as the first line, and again I can't see any way to find a 13th trick when South has 5 or more.

So I'll take the first line, but feel like there's probably something more complex..
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#3 User is offline   mikeh 

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Posted 2025-January-28, 03:01

The squeeze isn’t actually a squeeze

Run the hearts, cashing the spade ace at some early point. So reduce to xx x J x with dummy being Q void void AKJ10. North has, say K void Q and three clubs. You don’t know.where the queen is.

On your last heart, he pitches the spade king. Great, the queen is good but you have to reduce to Q void void AKJ.

Ok, you say, surely he wouldn’t pitch the spade king unless he also had the club queen?

Ok…as north you began with Kxx x KQxx xxxxx. Plan your defence. You had to come down to K void Q xxx, having pitched 2 clubs. Pitch another one and declarer will usually drop the queen offside…you’ve pitched 3 clubs and you don’t rate to have started with 6 of them. So you pitch the spade king….it surrenders trick 12 but not trick 13, and declarer is almost surely hooking the club now…unless he thinks you’re good enough to defend like this. Bear in mind that this event has some pretty good players in it.

What this means is that the squeeze is really a decision to play north for the club queen, in which case you could hook it early, winning if it’s onside unless he started with 5+ clubs.

Whether he holds the spade king is an illusion against WC defenders.

So…which is better? Hook north or south?

I think it very close since the ‘squeeze’ has an extra chance, over an immediate club hook when north has 5+ clubs to the queen….you can’t pick up Qxxxx in south by cashing AK and running the jack.

But hooking north loses to Qx in south, while playing to hook south picks up Qx in north.

Is Qxxxx in north along with diamond queen and spade king enough to overcome the squeeze line losing to Qx in south?

If north has five clubs he probably has shorter spades than does south, reducing the odds of his holding the spade king.

I simply am not good enough to calculate the odds. I’ve also seen the hand, so can’t credibly claim that I ‘know’ how I’d play it. I ‘think’ I’d play for south to have the queen, which is a tad over 50% since this line also wins when north has Qx or Q.

There is a third line but not one I’d expect anyone to take…club AK then ruff, picking up Qxx in either hand as well as Qx in either hand. Qxx is less likely than the odds of south holding Qxxx.
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#4 User is online   smerriman 

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Posted 2025-January-28, 04:32

I'm not following that at all. Why is the spade king relevant? The squeeze I meant was a minor suit squeeze which appears legitimate to me; if North holds the club queen they have to discard down to QQxx setting up your long club, as long as you don't take the finesse early. So doesn't that work no matter how many clubs they started with, irregardless of who has the spade king, thus 50%?

But I get the chance of South having Q, Qx, Qxx, Qxxx, or xxxxx+ as 40%, not just over 50%?
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#5 User is offline   lamford 

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Posted 2025-January-28, 07:21

The chance of North holding the queen of diamonds when he led the king against a grand is 100%. The trumps were 1-1 (I think I should have told you that). A posteriori, the chance of the queen of clubs being with South is 12:10 on, and with North 10:12 against. However, this is information the oppoentns chose to give you s o is unreliable. An expert North, not holding the queen of clubs, would lead a trump and with the queen of clubs would lead the king of diamonds. And Mystic Meg with Qxx of clubs would lead a club. I think both of these are above expert, however, and I would play for South to have the queen of clubs, just on available spaces.
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#6 User is offline   mikeh 

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Posted 2025-January-28, 10:43

View Postsmerriman, on 2025-January-28, 04:32, said:

I'm not following that at all. Why is the spade king relevant? The squeeze I meant was a minor suit squeeze which appears legitimate to me; if North holds the club queen they have to discard down to QQxx setting up your long club, as long as you don't take the finesse early. So doesn't that work no matter how many clubs they started with, irregardless of who has the spade king, thus 50%?

But I get the chance of South having Q, Qx, Qxx, Qxxx, or xxxxx+ as 40%, not just over 50%?

How to you propose to get back to dummy?
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#7 User is online   smerriman 

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Posted 2025-January-28, 11:57

 mikeh, on 2025-January-28, 10:43, said:

How to you propose to get back to dummy?

I don't need to get back to dummy. My line is cashing the diamond ace, spade ace, and all trumps, leaving me with 53J8 in hand opposite AKJT. I then finesse the club and drop North's queen, as they had to reduce to 3 clubs to keep the diamond. Isn't this just an automatic simple squeeze? What am I missing?

If you think finessing South is over 50%, it sounds like you're making when they have Qxxxx. The finesse is a 12th trick, where is your 13th?
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#8 User is online   smerriman 

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Posted 2025-January-28, 13:48

View Postlamford, on 2025-January-28, 07:21, said:

I think both of these are above expert, however, and I would play for South to have the queen of clubs, just on available spaces.

But if North has the queen you have a 100% line, and if South holds the queen you also need them to have 4 or less to find a 13th trick (this line also making if North has stiff Q or Qx, but that doesn't add up to much). Doesn't that make playing North for it much better?

(Also, it's 12:11, not 12:10, since this decision is prior to leading the first club.)
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#9 User is offline   lamford 

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Posted Yesterday, 08:45

View Postsmerriman, on 2025-January-28, 13:48, said:

But if North has the queen you have a 100% line, and if South holds the queen you also need them to have 4 or less to find a 13th trick (this line also making if North has stiff Q or Qx, but that doesn't add up to much). Doesn't that make playing North for it much better?

(Also, it's 12:11, not 12:10, since this decision is prior to leading the first club.)

No, it is 12:10. With some reservations. You cannot take into account the small diamond played by South, but can take into account the king and queen of diamonds in the available spaces calculation.

You cannot combine the ruffing club finesse with the squeeze on North as you need a trump entry if you play South for Qx(x)(x) in clubs. If North had Qxx(x) in clubs and the KQ of diamonds, an expert would surely lead his second highest club, when only Mystic Meg would finesse. I would guess the queen of clubs with South is as high as 70%
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#10 User is offline   lamford 

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Posted Yesterday, 08:45

View Postsmerriman, on 2025-January-28, 13:48, said:

But if North has the queen you have a 100% line, and if South holds the queen you also need them to have 4 or less to find a 13th trick (this line also making if North has stiff Q or Qx, but that doesn't add up to much). Doesn't that make playing North for it much better?

(Also, it's 12:11, not 12:10, since this decision is prior to leading the first club.)

No, it is 12:10. With some reservations. You cannot take into account the small diamond played by South, but can take into account the king and queen of diamonds in the available spaces calculation.

You cannot combine the ruffing club finesse with the squeeze on North as you need a trump entry if you play South for Qx(x)(x) in clubs. If North had Qxx(x) in clubs and the KQ of diamonds, an expert would surely lead his second highest club, when only Mystic Meg would finesse. I would guess the queen of clubs with South is as high as 70%
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#11 User is online   smerriman 

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Posted Yesterday, 12:45

View Postlamford, on 2025-January-29, 08:45, said:

If North had Qxx(x) in clubs and the KQ of diamonds, an expert would surely lead his second highest club, when only Mystic Meg would finesse. I would guess the queen of clubs with South is as high as 70%

You stated in your earlier post that an expert North, with the queen of clubs, would lead the King of diamonds. Was this a typo?

If North really would lead a club whenever holding the queen, then sure, that expert logic is above me; will try a poll (currently unanimously in disagreement, though perhaps nonexperts). But you also said that the lead logic was above expert and you would play South for it solely on vacant spaces.. that doesn't look right.

produce 1000000
predeal west SA53, HKQJT982, DAJ, C8
predeal east SQT, HA763, D97, CAKJT5
condition hascard(north, KD) and hascard(north, QD) and diamonds(south)>=1 and hearts(north)==1
line1 = hascard(north,QC)
line2 = hascard(north,QC) and clubs(north)<=2 or hascard(south,QC) and clubs(south)<=4

action frequency(line1,0,1)
    0	  545408
    1	  454592

action frequency(line2,0,1)
    0	  587134
    1	  412866

Solely on vacant spaces, playing North for the queen wins 45.5% of the time; the other line only 41.3%.
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#12 User is offline   lamford 

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Posted Today, 07:39

I don't think there is any typo. If North has the KQ of diamonds then he does not have to lead a top diamond against the grand as that gives information to declarer. You should only include the KQ of diamonds in the vacant spaces calculations. You know that South has to have at least one diamond, or North would have bid with 9 of them. An expert North might reason: "If I lead a top diamond, declarer is likely to play my partner for the queen of clubs. If I don't declarer has no information to go on. Also, it seems that West has both AS and AD to have bid Blackwood rather than cue. East will have the AK clubs and a heart key card.

About half those in grand made it. Much depends on whether North would lead a club with the queen. He does not know dummy has the jack, ten, but he can see the benefit of the club lead. I think playing South for the queen of clubs is much better than playing North for it. Even though if South has Qxxxx or Qxxxxx in clubs we cannot make it
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#13 User is online   smerriman 

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Posted Today, 12:19

 lamford, on 2025-January-30, 07:39, said:

I don't think there is any typo.

Your first post said that an expert North, holding KQ of diamonds and the queen of clubs would surely lead a diamond. Your second post said that an expert North holding those cards would surely lead a club. Those are two completely opposite statements; you can't have meant both.

19 people have voted; 18 decided to lead a diamond, with the other leading a trump. Nobody has led a club, so they agree with your first statement, not your second.

Against any of those players, therefore, the first line is better, so I'll stick with that.
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