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What spade to play? drop or finesse?

#1 User is offline   Hanoi5 

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Posted 2012-September-12, 20:15



What would you play? Why?

View Postwyman, on 2012-May-04, 09:48, said:

Also, he rates to not have a heart void when he leads the 3.


View Postrbforster, on 2012-May-20, 21:04, said:

Besides playing for fun, most people also like to play bridge to win


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#2 User is offline   Phil 

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Posted 2012-September-12, 20:20

Not really close is it?
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Posted 2012-September-12, 20:24

View PostHanoi5, on 2012-September-12, 20:15, said:



What would you play? Why?


Google theory on vacant space. When you do, you will find that you can count West as having five vacant space to East's eleven (when the last small spade was played, you can count the known spades in the vacant space calculation). You might want to refine this a little. West opened first seat with AKJT7xx of hearts. If he had the A or K he would have opened 1. If you take the clubs into account, the vacant spaces would still be five to West and 9 in East. So what are the odds of finesse versus drop? Finesse is 64%, drop is 36% (values rounded).

If you decide you can't place the club honors, the odds are even more in favor of the finesse.

I guess I should show you how to get these numbers...

The math is West had five possible cards, only one can be the J... So the math is C(5,1) = 5. East has 9 spaces (if we give him the club AK), so his is C(9,1)= 9

So there are 14 combinations for the location of the jack (5 with West, 9 with East). This come to 5/14 = odds west has the jack or 35.7, the odds East has the jack is 9/14 = 62.3%.
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Posted 2012-September-12, 20:39

If we take a finesse, we want diamonds to be 3-3 since we can't ruff one anymore. If the drop works, then we can ruff a diamond and the diamonds can be distributed however they want. Finesse seems much more likely than 2-2 spades but requires the diamonds as well - I don't know how to calculate these probabilities but gut says finesse AND 3-3 diamonds is less likely than 2-2 spades so I'll try dropping.
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#5 User is offline   dwar0123 

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Posted 2012-September-12, 20:52

View PostQuantumcat, on 2012-September-12, 20:39, said:

If we take a finesse, we want diamonds to be 3-3 since we can't ruff one anymore. If the drop works, then we can ruff a diamond and the diamonds can be distributed however they want. Finesse seems much more likely than 2-2 spades but requires the diamonds as well - I don't know how to calculate these probabilities but gut says finesse AND 3-3 diamonds is less likely than 2-2 spades so I'll try dropping.

Finesse doesnt require a 3-3 break, it only requires rho has at least 3 diamonds which is a near sure thing as he would have pitched his diamonds on the hearts with two or fewer.

If finesse works, play two more top diamomds, if they split 3-3, pull trump, if they split 4-2, it is almost a sure thing rho has the 4 and you're still good to go to ruff the loser.
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#6 User is offline   Quantumcat 

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Posted 2012-September-12, 21:20

View Postdwar0123, on 2012-September-12, 20:52, said:

Finesse doesnt require a 3-3 break, it only requires rho has at least 3 diamonds which is a near sure thing as he would have pitched his diamonds on the hearts with two or fewer.

If finesse works, play two more top diamomds, if they split 3-3, pull trump, if they split 4-2, it is almost a sure thing rho has the 4 and you're still good to go to ruff the loser.

Thanks, I didn't think of that. I guess if he had three or four including the jack, he would not pitch, since we will see the jack drop, then just draw his trump and not worry about ruffing a diamond. I wonder why this is a question then? The natural thing to do with no thought is to finesse (pre-empters usually have singleton trumps). I thought I noticed something that meant we couldn't take it (the need to ruff a diamond). But it turned out to not be a problem after all.
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#7 User is offline   sailoranch 

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Posted 2012-September-12, 21:28

Also, West might have chosen to bid higher with a four card diamond suit, so an overruff seems less likely.
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Posted 2012-September-12, 21:45

There is no need to consider ruffing a diamond. Surely you have a diamond-club squeeze on East if you can safely pick up the spades.

If West has a four diamonds, he would have shifted to his singleton club after cashing the two hearts (he would be 1-7-4-1), and while he might have five diamonds, with a club void he NEVER would have returned the !hJ.. he would have returned a low suggesting a club return.... Q.E.D.

So if east has four diamonds, you can squeeze him in the minors. If he has three diamonds, diamonds run, and we don't suspect he will have two diamonds because of the lack of a club shift.
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#9 User is offline   dwar0123 

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Posted 2012-September-12, 22:17

View Postinquiry, on 2012-September-12, 21:45, said:

There is no need to consider ruffing a diamond. Surely you have a diamond-club squeeze on East if you can safely pick up the spades.

If West has a four diamonds, he would have shifted to his singleton club after cashing the two hearts (he would be 1-7-4-1), and while he might have five diamonds, with a club void he NEVER would have returned the !hJ.. he would have returned a low suggesting a club return.... Q.E.D.

So if east has four diamonds, you can squeeze him in the minors. If he has three diamonds, diamonds run, and we don't suspect he will have two diamonds because of the lack of a club shift.

How do you transfer the club threat if lho has the ace or king?
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#10 User is offline   sailoranch 

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Posted 2012-September-12, 22:22

View Postdwar0123, on 2012-September-12, 22:17, said:

How do you transfer the club threat if lho has the ace or king?


Unlikely on West's preempt?
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#11 User is offline   Phil 

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Posted 2012-September-12, 22:28

View Postinquiry, on 2012-September-12, 21:45, said:

There is no need to consider ruffing a diamond. Surely you have a diamond-club squeeze on East if you can safely pick up the spades.

If West has a four diamonds, he would have shifted to his singleton club after cashing the two hearts (he would be 1-7-4-1), and while he might have five diamonds, with a club void he NEVER would have returned the !hJ.. he would have returned a low suggesting a club return.... Q.E.D.

So if east has four diamonds, you can squeeze him in the minors. If he has three diamonds, diamonds run, and we don't suspect he will have two diamonds because of the lack of a club shift.


You killed your squeeze entry when you checked for J stiff.
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#12 User is offline   dwar0123 

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Posted 2012-September-12, 22:28

View Postsailoranch, on 2012-September-12, 22:22, said:

Unlikely on West's preempt?

Actually, lho only needs the 5 of clubs, but still what is the fear in ruffing the diamond?
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#13 User is offline   sailoranch 

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Posted 2012-September-12, 22:54

View Postdwar0123, on 2012-September-12, 22:28, said:

Actually, lho only needs the 5 of clubs, but still what is the fear in ruffing the diamond?


I don't know, I'm expecting OP to tell us?
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Posted 2012-September-12, 23:03

View PostPhil, on 2012-September-12, 22:28, said:

You killed your squeeze entry when you checked for J stiff.


Well I wasn't playing the hand. I would NOT have played the way this hand was played. I would have taken a first round finesse in spades (the 0=4 split is more likely than 1=3 with the club jack being singleton (6 versus 10 vacant spaces). This small difference (first round hook) also might save you when West was 1-7-0-5 (West did return the heart jack).


Not that it is relevant, but if East does have four plus diamonds, and you wanted to play the squeeze, you can STILL DO SO after playing a diamond to the king. East will have to come down to three diamonds (else your diamonds run) and his top club. You then throw him in with his club for a forced lead away from the !DJ. If he leads the !DJ, he will block your enjoyment of your last diamond in your hand, but you will win a high diamond in hand, then the D-10 in dummy and cash your club queen. Of course there will be no way to get a diamond count on EAST, you will have to guess if diamonds were 3-3 all along, or if East had four (or more)... and even if east had four diamonds, the JACK doubleton might be offside.... Another reason to take the first round spade hook.
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Posted 2012-September-12, 23:45

View Postinquiry, on 2012-September-12, 23:03, said:

Well I wasn't playing the hand. I would NOT have played the way this hand was played. I would have taken a first round finesse in spades (the 0=4 split is more likely than 1=3 with the club jack being singleton (6 versus 10 vacant spaces). This small difference (first round hook) also might save you when West was 1-7-0-5 (West did return the heart jack).


Not that it is relevant, but if East does have four plus diamonds, and you wanted to play the squeeze, you can STILL DO SO after playing a diamond to the king. East will have to come down to three diamonds (else your diamonds run) and his top club. You then throw him in with his club for a forced lead away from the !DJ. If he leads the !DJ, he will block your enjoyment of your last diamond in your hand, but you will win a high diamond in hand, then the D-10 in dummy and cash your club queen. Of course there will be no way to get a diamond count on EAST, you will have to guess if diamonds were 3-3 all along, or if East had four (or more)... and even if east had four diamonds, the JACK doubleton might be offside.... Another reason to take the first round spade hook.

So lets say the first round finesse works.

How is your line safer in each of these conditions?

0-4: Diamond to king, second trump finesse, 2 top diamonds, pulling last two trumps if diamonds split or ruffing a diamond if they don't.

1-3: Ace of trump, to be sure the split was in fact 1-3, then test diamomd split as above.

2-2: As above but instantly claim.

I see losing lie of the cards with your method, unlikely perhaps, but I don't yet see anything that your method protects against over testing diamonds.
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#16 User is offline   MrAce 

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Posted 2012-September-13, 00:37

View Postdwar0123, on 2012-September-12, 20:52, said:

Finesse doesnt require a 3-3 break, it only requires rho has at least 3 diamonds which is a near sure thing as he would have pitched his diamonds on the hearts with two or fewer.

If finesse works, play two more top diamomds, if they split 3-3, pull trump, if they split 4-2, it is almost a sure thing rho has the 4 and you're still good to go to ruff the loser.



Amen

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#17 User is offline   gnasher 

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Posted 2012-September-13, 02:42

At trick four, comparing the OP's spade to the ace with Ben's spade to the jack:

The first-round finesse loses when spades are J-xxx. It gains when spades are void-Jxxx, but only if East has J. When West has a spade void and J, we can recover by taking a diamond finesse and using the extra entry to pick up trumps.

Given that East has AK and the three low spades, the vacant places are 6:7, so a 0=4 break is only slightly more likely than J=xxx. If we think we're going to recover on half of the 0=4 breaks, that makes a spade to the ace better.

However, with Jxxx x xxx AKxxx, East could have beaten us by force by discarding two diamonds on the hearts. That argues in favour of the first-round finesse.

But the most compelling argument is the bidding. With void AKJ10xxx xxx xxx, first at favourable, most people would open 4. I think this outweighs the other considerations, so I'd start with a spade to the ace.


There is one other line that isn't relevant given the bidding, but is vaguely interesting. Suppose that you play a spade to the ace at trick four, and LHO shows out. If East has four damonds, you can make by playing a club to the queen. If he returns a diamond, that gives you the extra entry for taking two trump finesses. If he returns a club, you ruff, play a diamond to the king, take a spade finesse, ruff the fourth diamond in dummy, and lead a club to trump-coup him.
... that would still not be conclusive proof, before someone wants to explain that to me as well as if I was a 5 year-old. - gwnn
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#18 User is offline   rhm 

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Posted 2012-September-13, 03:11

View Postgnasher, on 2012-September-13, 02:42, said:

At trick four, comparing the OP's spade to the ace with Ben's spade to the jack:

The first-round finesse loses when spades are J-xxx. It gains when spades are void-Jxxx, but only if East has J. When West has a spade void and J, we can recover by taking a diamond finesse and using the extra entry to pick up trumps.

Given that East has AK and the three low spades, the vacant places are 6:7, so a 0=4 break is only slightly more likely than J=xxx. If we think we're going to recover on half of the 0=4 breaks, that makes a spade to the ace better.

However, with Jxxx x xxx AKxxx, East could have beaten us by force by discarding two diamonds on the hearts. That argues in favour of the first-round finesse.

But the most compelling argument is the bidding. With void AKJ10xxx xxx xxx, first at favourable, most people would open 4. I think this outweighs the other considerations, so I'd start with a spade to the ace.


There is one other line that isn't relevant given the bidding, but is vaguely interesting. Suppose that you play a spade to the ace at trick four, and LHO shows out. If East has four damonds, you can make by playing a club to the queen. If he returns a diamond, that gives you the extra entry for taking two trump finesses. If he returns a club, you ruff, play a diamond to the king, take a spade finesse, ruff the fourth diamond in dummy, and lead a club to trump-coup him.


Amen

+1

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#19 User is offline   phil_20686 

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Posted 2012-September-13, 07:10

I think you should drop. Lots of people open 4h with 17(32) shape and a suit this good, and with 17(41) it is basically certain. It is well above the vacant spaces odds that he has two spades imo.

I would also assume that rho started with 6 clubs. If he started with 5 and came down to three, he would be letting it through on some layouts where you can now ruff down the clubs. Especially if he has two spades. E.g. 2155 is now impossible, as you would get a late trump entry.

Besides, most defenders don't think like this, they pitch clubs quickly as long as they have more than dummy, and then have a long thing about which suit to shorten only when its forced on them.
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#20 User is offline   FrancesHinden 

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Posted 2012-September-14, 15:56

View Postphil_20686, on 2012-September-13, 07:10, said:

I think you should drop. Lots of people open 4h with 17(32) shape and a suit this good, and with 17(41) it is basically certain. It is well above the vacant spaces odds that he has two spades imo.

I would also assume that rho started with 6 clubs. If he started with 5 and came down to three, he would be letting it through on some layouts where you can now ruff down the clubs. Especially if he has two spades. E.g. 2155 is now impossible, as you would get a late trump entry.

Besides, most defenders don't think like this, they pitch clubs quickly as long as they have more than dummy, and then have a long thing about which suit to shorten only when its forced on them.


I was thinking along these lines until I got to phil's post. It obviously depends on opponents, but when I saw inquiry suggesting we should worry about LHO being 0715 I thought that was getting very silly.
A favourable 3H opening with AKJ10xxx in the suit looks likely to be 2722 against most good English opponents. You really need to know more about their pre-empt style before deciding how far to take this account.
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