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Mixed strategies

#1 User is offline   wyman 

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Posted 2012-March-22, 08:15



MP

T1: 5, 3, 9, 10
T2: 3, 4, Q, A
T3: 2, J, 8, 3
T4: 6, 5, ?

Righty is world class. Under what circumstances, if any, do you play the K here?
"I think maybe so and so was caught cheating but maybe I don't have the names right". Sure, and I think maybe your mother .... Oh yeah, that was someone else maybe. -- kenberg

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#2 User is offline   Bbradley62 

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Posted 2012-March-22, 08:21

not sure it matters, so maybe just stalling... what is the form of scoring, or is that part of the question?
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#3 User is offline   wyman 

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Posted 2012-March-22, 08:24

View PostBbradley62, on 2012-March-22, 08:21, said:

not sure it matters, so maybe just stalling... what is the form of scoring, or is that part of the question?


MP

The full hand is a red herring, I'm just wondering how to play the spade suit.
"I think maybe so and so was caught cheating but maybe I don't have the names right". Sure, and I think maybe your mother .... Oh yeah, that was someone else maybe. -- kenberg

"...we live off being battle-scarred veterans who manage to hate our opponents slightly more than we hate each other.” -- Hamman, re: Wolff
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#4 User is offline   ArtK78 

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Posted 2012-March-22, 08:57

The only time it is clearly "right" to play the K on this trick is when RHO has AJ doubleton of spades. That seems very unlikely given the play to tricks one and three, as it appears that the clubs are 5-1 with length on your left.

Generally speaking, RHO, being "world class," would not win the first round of spades unless he had no choice - meaning that he held a singleton A or a doubleton AJ. Neither of these possibilities seems likely, but if you are going to assume that RHO's play at trick two was not lazy, then you should play the K.

Query: Does RHO know you? Could he be playing mind games with you by taking the A on the first round hoping that you would play him for AJ doubleton?

Another point to ponder. RHO made no attempt to attack the only outside entry to the spade suit - the A. I don't know where I am going with this point, but it is something to consider.
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#5 User is offline   Phil 

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Posted 2012-March-22, 09:04

I think you pay off to RHO's Grosvenor holding Axx.

Winning with Axx would be such a bad play. You are on your way to misguessing the suit and the entry situation is such that that ducking leads to a likely set.

Might it be better to start spades by leading low to the T?
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#6 User is offline   wyman 

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Posted 2012-March-22, 09:17

View PostPhil, on 2012-March-22, 09:04, said:

I think you pay off to RHO's Grosvenor holding Axx.

Winning with Axx would be such a bad play. You are on your way to misguessing the suit and the entry situation is such that that ducking leads to a likely set.

Might it be better to start spades by leading low to the T?


I erred by only giving dummy 1 outside entry. Maybe I should have given him the AK tight of hearts.

I played this suit combo last night against (euphemistically) "novice" opps [I had AQ dub opp xxx in dummy, and clubs were 6-2, but righty still led a diamond lol], and I played low to the Q, low to the 9, and RHO won with AJ tight. I lamented that if JLall was on my right, I would have gotten it right. But this prompted me to wonder if it's right some (admittedly very small) fraction of the time to play A from Axx just to protect when you have AJ tight.
"I think maybe so and so was caught cheating but maybe I don't have the names right". Sure, and I think maybe your mother .... Oh yeah, that was someone else maybe. -- kenberg

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#7 User is offline   phil_20686 

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Posted 2012-March-22, 16:28

View Postwyman, on 2012-March-22, 09:17, said:

I erred by only giving dummy 1 outside entry. Maybe I should have given him the AK tight of hearts.

I played this suit combo last night against (euphemistically) "novice" opps [I had AQ dub opp xxx in dummy, and clubs were 6-2, but righty still led a diamond lol], and I played low to the Q, low to the 9, and RHO won with AJ tight. I lamented that if JLall was on my right, I would have gotten it right. But this prompted me to wonder if it's right some (admittedly very small) fraction of the time to play A from Axx just to protect when you have AJ tight.


The answer to your question is yes. Sometimes you should win from Ax to protect yourself. Afterall, if you never win the ace except stiff ace, then they are 100% to pick up AJ offside. Moreover, a perfect defender can take advantage of this by winning with Ax or Axx so that you try and fail to drop the J next. Of course, this strategy works better when the defenders have the spade 9, st you lose 3 spades establishing it if rho wins from Ax and you lose 3 tricks if you must estabilish the 5th spade.
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#8 User is offline   bd71 

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Posted 2012-March-22, 17:38

How many boards do you think you need to play against someone for enough analagous situations to come up for the game theoretic issues to come into play? It's this a practical consideration or is it just theory?

Asked another way, have you EVER made a play ATT in which you were bringing second-order game theory considerations into play?
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#9 User is offline   wyman 

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Posted 2012-March-23, 08:20

View Postbd71, on 2012-March-22, 17:38, said:

Asked another way, have you EVER made a play ATT in which you were bringing second-order game theory considerations into play?


I have not [edit: except in bar games with friends], but I do remember Justin telling a story in Louisville about how he was in a sting cuebid situation with xx in one suit and a void in another but knew he had plenty of tricks for a grand. I think it was Helness on his left (but maybe he can tell the story), and Justin thought about sting cue-ing the xx, but thought LHO would see right through it, so he cuebid his void, bid the grand, and without thinking about it Helness led into his void.

IIRC, his partner had the A in the xx suit, so it was moot, but the point of the story is that I think it does happen when you have enough history with an opp [edit2: or at least enough to know that he knows what the 'right' play is].
"I think maybe so and so was caught cheating but maybe I don't have the names right". Sure, and I think maybe your mother .... Oh yeah, that was someone else maybe. -- kenberg

"...we live off being battle-scarred veterans who manage to hate our opponents slightly more than we hate each other.” -- Hamman, re: Wolff
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#10 User is offline   phil_20686 

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Posted 2012-March-23, 09:16

View Postbd71, on 2012-March-22, 17:38, said:

How many boards do you think you need to play against someone for enough analagous situations to come up for the game theoretic issues to come into play? It's this a practical consideration or is it just theory?

Asked another way, have you EVER made a play ATT in which you were bringing second-order game theory considerations into play?


People are too random for something this small to ever matter. Sometimes they will win the ace for no reason beyond they had an ace.

Having said that, I have certainly engaged in this type of behaviour in some false card situations. Playing the 9 from 9x and 9xx to protect other positions is a reasonably common example.

An example is this layout

AJ9x
Tx
Kxxx

Here you must play the T under the K Tx to protect the holding of QT. In pratice against many club players if you see the ten, you should assume they have QT.
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#11 User is offline   han 

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Posted 2012-March-23, 09:41

Is it right to play small to an honor at trick 2? I thought that small to the 10 is the best play for 4 tricks in isolation, you lose against Axx or xxxx onside but you win against Jxx, AJxx or Jxxx onside, that's much better. You can't pick up Ax onside anyway.

It's difficult to say here because the complete hand is so complicated. And of course with a 6-2 fit it is best to play to the honors twice, I wonder if somebody confused the two suit combinations.
Please note: I am interested in boring, bog standard, 2/1.

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#12 User is offline   han 

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Posted 2012-March-23, 09:47

By the way, how do you play this suit combination:



You lead the 8 from hand and LHO, a well known expert who certainly doesn't know you, plays low smoothly.

This situation came up almost two years ago when I played the summer fast pairs with Roger. I decided that LHO would almost always have played an honor holding H10x, so I asked for the jack. Whether it was the "right" play I will never know, but it certainly was the winning play because LHO held KQx.

The expert was very nice about it btw, when we met him again the next session he insisted on sitting on my right. This worked out even worse for him because his sponsor now had to make all the decisions that round, two more good scores for Roger and me!
Please note: I am interested in boring, bog standard, 2/1.

- hrothgar
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#13 User is offline   phil_20686 

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Posted 2012-March-23, 09:48

View Posthan, on 2012-March-23, 09:47, said:

How do you play this suit combination:


with a microscope?
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#14 User is offline   phil_20686 

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Posted 2012-March-23, 09:52

View Posthan, on 2012-March-23, 09:41, said:

Is it right to play small to an honor at trick 2? I thought that small to the 10 is the best play for 4 tricks in isolation, you lose against Axx or xxxx onside but you win against Jxx, AJxx or Jxxx onside, that's much better. You can't pick up Ax onside anyway.


Small to the ten is best for 4 tricks in isolation, but on this hand you might need any of 1 two or three spade tricks. Also you have the nine, so you can establish the spades by force for 3 tricks. The danger here with low to the ten is that if it loses to the J a switch to the heart K holds you to no spade tricks, and now you are certainly off.
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#15 User is offline   han 

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Posted 2012-March-23, 09:55

View Postphil_20686, on 2012-March-23, 09:48, said:

with a microscope?


I clicked the wrong button!
Please note: I am interested in boring, bog standard, 2/1.

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#16 User is offline   han 

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Posted 2012-March-23, 09:56

View Postphil_20686, on 2012-March-23, 09:52, said:

Small to the ten is best for 4 tricks in isolation, but on this hand you might need any of 1 two or three spade tricks. Also you have the nine, so you can establish the spades by force for 3 tricks. The danger here with low to the ten is that if it loses to the J a switch to the heart K holds you to no spade tricks, and now you are certainly off.


Absolutely agree with you, it's a difficult hand. It's also interesting that RHO did NOT shift to a heart.
Please note: I am interested in boring, bog standard, 2/1.

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#17 User is offline   phil_20686 

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Posted 2012-March-23, 10:00

View Posthan, on 2012-March-23, 09:47, said:

By the way, how do you play this suit combination:



You lead the 8 from hand and LHO, a well known expert who certainly doesn't know you, plays low smoothly.

This situation came up almost two years ago when I played the summer fast pairs with Roger. I decided that LHO would almost always have played an honor holding H10x, so I asked for the jack. Whether it was the "right" play I will never know, but it certainly was the winning play because LHO held KQx.

The expert was very nice about it btw, when we met him again the next session he insisted on sitting on my right. This worked out even worse for him because his sponsor now had to make all the decisions that round, two more good scores for Roger and me!


This is nice, its one where you definitely benefit from being unknown, as vs another expert and expert will randomise, but vs a player who might not imagine the false card you should always rise from HTx.
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#18 User is offline   dboxley 

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Posted 2012-April-06, 19:43

Seems like the K is right against a real wcp but it depends on his/her opinion of you as a player. This is a situation where you have a distinct advantage if you are unknown to him/her since there is no double think.
BTW, I answered this before reading the previous posts, after reading them I realized that anything I said is superfluous. Never mind...
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#19 User is offline   dave_w 

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Posted 2012-April-10, 04:11

Well on this hand I don't think it matters what you do. You'll have 9 (of course MP considerations come in to it). I'd play small to the King and small to the Queen. The cards the opponents play are mostly irrelevant, otherwise you'll pay out to false carding (small to an honour the second time is superior to small to the 9 as you can pick up Jx but not Ax). So I'd try and drop the doubleton Jack.

Also this reminds me of an expert story (I think they were Polish) dummy had KQJ9x of a suit and no outside entry. Declarer with xx leads small to the King and the expert won the Ace. On the second round they played small to the 9 (it had to be singleton Ace or they would have ducked to cut him off from dummy) and lost to the Ten (AT doubleton originally), and took no tricks in the suit.
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