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Stephen, I believe _The Encylopedia_ and a few other references explain why your reasoning is flawed and that this is not a Restricted Choice situation.
More like Monty Hall or "The Lady and the Tiger". It's an illusion that you get any new information because you don't get any information that =matters=.
"The difference that makes no difference is no difference."
...and contrary to Stephen's occasionally rude comments, I=do= know what I'm talking about here so I'm going to clear up something that has not been made explicit until now.
The true falsecard situation in this combination is when an opponent holds Jxx or Txx in front of AQ98x.
If you know your opponent will never falsecard with this holding the proper play on T2 is to play the A.
The play of the 8 or 9 is effectively insurance against a possible falsecard by LHO through dropping the J or T as if forced to here.
Winning the K when you don't need to holding KJ or KT is a con that is far more easily seen through than the J or T from hxx falsecard.
The bottom line is not to commit yourself until you have to in these situations. Get a more detailed count on the hand as much as you have to or can afford to before touching holdings like these a 2nd time.
Q or 9, is there a difference
#22
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Posted 2007-June-22, 18:40
Foo, if you truly understood restricted choice, and were actually right about this, you could make a logical argument why I am wrong, or deconstruct my statements and tell me where I am wrong. Instead you just say "encyclopedia explains why", and aren't pointing out where my logic is faulty. I call BS, there is nowhere in the encyclopedia that explains why I am wrong, because I am not wrong. If you really believe this is so, please pick out which specific statement(s) I make below is/are incorrect, that you disagree with, and explain why. If all you can come up with is "I think this book says you're wrong", then you don't truly understand what those books are talking about.
In your posts you keep on listing
the JT tight possibility as 3.4%,
and the T stiff possibility as 2.8%.
, but not mentioning the possibility of J stiff.
Where restricted choice comes in is in what probability you assign to JT tight. You cannot assign the full a priori probability of 3.4% to JT tight, because opponent played the T, and he will not play the T all the time from that combination! He is supposed to play it only about half the time. If he did play the T all the time, one could employ the counter strategy of hooking the Q when the T appears, but hooking the low when the J appeared, and make him worse off than someone who randomized their play from JT. But real opps randomize, and the best you can do is consistently pick up both stiff T and stiff J, and give up to JT (if comparing the hook Q & hook low lines). Now for hook low vs. play ace, as discussed above that depends on the falsecarding frequencies. The KT/KJ possibilities are not relevant when comparing the finesse lines since both lose 2 tricks in that case.
The right way to think about these restricted choice problems is to either compare probability of opponent holding JT AND he chose to play T (50%) = 1.7%
vs. the possibility of T stiff,
OR to take the full 3.4% probability, but count both the T stiff & J stiff cases, treating both honors as identical since the goal is to optimize your strategy for both cases, T appearing or J appearing first round from RHO, and logically the strategy should be the same since those cards are effectively the same here, assuming the defender is not pursing some strange never or always falsecard strategy from JT tight.
How am I wrong here? Where in the encyclopedia does it say this reasoning is flawed?
If restricted choice did not apply, and the JT tight probability was not reduced properly, the conclusion that would be reached that it is superior to play the Q than to hook low again, because 3.4 > 2.8. But as stated above it does apply, and this isn't true.
You DO get information that matters here when RHO wins the T. The info gained is that T stiff is more likely than JT doubleton, because part of the time from JT doubleton he would have played the J, whereas from T stiff he has no choice.
In your posts you keep on listing
the JT tight possibility as 3.4%,
and the T stiff possibility as 2.8%.
, but not mentioning the possibility of J stiff.
Where restricted choice comes in is in what probability you assign to JT tight. You cannot assign the full a priori probability of 3.4% to JT tight, because opponent played the T, and he will not play the T all the time from that combination! He is supposed to play it only about half the time. If he did play the T all the time, one could employ the counter strategy of hooking the Q when the T appears, but hooking the low when the J appeared, and make him worse off than someone who randomized their play from JT. But real opps randomize, and the best you can do is consistently pick up both stiff T and stiff J, and give up to JT (if comparing the hook Q & hook low lines). Now for hook low vs. play ace, as discussed above that depends on the falsecarding frequencies. The KT/KJ possibilities are not relevant when comparing the finesse lines since both lose 2 tricks in that case.
The right way to think about these restricted choice problems is to either compare probability of opponent holding JT AND he chose to play T (50%) = 1.7%
vs. the possibility of T stiff,
OR to take the full 3.4% probability, but count both the T stiff & J stiff cases, treating both honors as identical since the goal is to optimize your strategy for both cases, T appearing or J appearing first round from RHO, and logically the strategy should be the same since those cards are effectively the same here, assuming the defender is not pursing some strange never or always falsecard strategy from JT tight.
How am I wrong here? Where in the encyclopedia does it say this reasoning is flawed?
If restricted choice did not apply, and the JT tight probability was not reduced properly, the conclusion that would be reached that it is superior to play the Q than to hook low again, because 3.4 > 2.8. But as stated above it does apply, and this isn't true.
You DO get information that matters here when RHO wins the T. The info gained is that T stiff is more likely than JT doubleton, because part of the time from JT doubleton he would have played the J, whereas from T stiff he has no choice.
#23
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Posted 2007-June-22, 21:38
Stephen Tu, on Jun 22 2007, 07:40 PM, said:
Foo, if you truly understood restricted choice, and were actually right about this, you could make a logical argument why I am wrong, or deconstruct my statements and tell me where I am wrong.
In your posts you keep on listing the JT tight possibility as 3.4%, and the T stiff possibility as 2.8%, but not mentioning the possibility of J stiff.
In your posts you keep on listing the JT tight possibility as 3.4%, and the T stiff possibility as 2.8%, but not mentioning the possibility of J stiff.
Logic point 1: The play of T1 of this suit makes it =impossible= for the suit to have split KT54+J or J+KT54
There can be no J stiff.I don't mention impossibilities because they don't matter...
Logic point2: I will not quote _The Encylopedia_'s section on Restricted Choice and the logical fallacies that are sometimes associated with it. I have given the reference. Even the hint as to what the problem is.
I have pointed out =repeatedly= that you get no information beyond the original apriori probabilities from the winning of the T on T1 that tells you anything about how to play the suit on T2 in the suit. If there was, it would be possible to construct a logically convincing argument as to how to play the suit on T2 based on that fact. Instead, the best way to play the suit is based =solely= on whether one thinks it is more likely that LHO will falsecard or not on T2.
That is not a Restricted Choice based argument or strategy.
The arguments have been made. I have pointed out the flaws in your statements. I given references to back up my analysis of those flaws.
You simply don't want to accept them.
#24
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Posted 2007-June-22, 22:20
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Logic point 1: The play of T1 of this suit makes it =impossible= for the suit to have split KT54+J or J+KT54 smile.gif There can be no J stiff.
I don't mention impossibilities because they don't matter...
I don't mention impossibilities because they don't matter...
The first matters in the context of an overall strategy of what to do when RHO wins either with the T or the J. Logically your strategy should be the same either way.
It's OK to say you will ignore the first case, but then in your calculations you also must state the probability of JT doubleton as 1.7%, not 3.4% to be consistent. If you ignore cases where RHO has the stiff J, you also must ignore cases where RHO had JT & chose to play the J instead. RHO will NOT play T from JT 100% of the original 3.4%, he will only play it half of that.
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Logic point2: I will not quote _The Encylopedia_'s section on Restricted Choice and the logical fallacies that are sometimes associated with it. I have given the reference. Even the hint as to what the problem is.
You are dodging. You will not quote, because there is no quote there that supports your thesis and refutes mine.
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I have pointed out =repeatedly= that you get no information beyond the original apriori probabilities from the winning of the T on T1 that tells you anything about how to play the suit on T2 in the suit.
Yes, you repeatedly make statements without any valid logic to back them up. Saying the same thing without any cogent argument to support it over & over again doesn't make it true. Restricted choice absolutely does apply, when comparing the two hook lines, comparing whether low to the Q catering to JT doubleton is better or worse than hooking low catering to T stiff. Do you agree that hooking low is better than hooking Q? If so, how does that follow when you state that the probability of JT is 3.4% while the probability of T stiff is only 2.8%?
(Answer: because probability of JT, RHO playing the T is really only 1.7%, which is less than 2.8%, this is an application of restricted choice).
Restricted choice does not apply exactly in comparing hooking low vs. playing the ace second round, as the K & T aren't equals & you have to assign some arbitrary probability to the various falsecards based on your experience with players of various skill levels. For this part I will agree with you. But you are wrong that there is no application at all of restricted choice in this problem.
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I have pointed out the flaws in your statements. I given references to back up my analysis of those flaws. You simply don't want to accept them
I made quite a few statements. You picked out exactly one above to pick at here, and I have now explained why you are incorrect. You refer people to the Encyclopedia, but refuse to quote the passage, because there really aren't any that back your claim. I think most people here will agree that you've failed miserably to make your case.
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Posted 2007-June-22, 22:43
bottom p382 "a mistake to avoid" to top p383 Ex 4 and 5
(ex 4 is KJ9+xxx; ex 5 is AQTxxx+xxx)
I am !not! wasting my time copying it verbatum for you. I simply will not be goaded into such stupidity.
The rest of the write-up is equally instructive.
The bottom line here is that you do not receive enough information from the play on T1 for it to influence the odds enough, and hence your play enough, on T2.
"The difference that makes no difference =is= no difference."
The odds do not change enough based on the play of T1 for it to affect your plans. Therefore this is !not! a Restricted Choice situation.
Had the cards been 54+KJT, or x+KJTx would RHO =ever= win T1 with anything but the T?
No. He has no reason to randomize his choice or to falsecard.
If Restricted Choice held, you would be able to pick which card to play on T2 based on the play of T1 to maximize your chances. You can not. Therefore it is not an issue.
Once you can handle it, I strongly suggest you (re)read _Master Play_ by Terence Reese on this topic.
..and using impossiblities as "props" for your arguments is such a logical fallacy as to make logical discussion of any topic that you bring them to impossible.
I haven't dodged even a little bit. The students who actually want to learn have all the logic and references they need on this topic. Yourself included if you so desire.
I'm done here. Go argue with someone else.
(ex 4 is KJ9+xxx; ex 5 is AQTxxx+xxx)
I am !not! wasting my time copying it verbatum for you. I simply will not be goaded into such stupidity.
The rest of the write-up is equally instructive.
The bottom line here is that you do not receive enough information from the play on T1 for it to influence the odds enough, and hence your play enough, on T2.
"The difference that makes no difference =is= no difference."
The odds do not change enough based on the play of T1 for it to affect your plans. Therefore this is !not! a Restricted Choice situation.
Had the cards been 54+KJT, or x+KJTx would RHO =ever= win T1 with anything but the T?
No. He has no reason to randomize his choice or to falsecard.
If Restricted Choice held, you would be able to pick which card to play on T2 based on the play of T1 to maximize your chances. You can not. Therefore it is not an issue.
Once you can handle it, I strongly suggest you (re)read _Master Play_ by Terence Reese on this topic.
..and using impossiblities as "props" for your arguments is such a logical fallacy as to make logical discussion of any topic that you bring them to impossible.
I haven't dodged even a little bit. The students who actually want to learn have all the logic and references they need on this topic. Yourself included if you so desire.
I'm done here. Go argue with someone else.
#26
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Posted 2007-June-22, 22:53
Aw don't stop, this has certainly been instructive for all of us!
Please let me know about any questions or interest or bug reports about GIB.
#27
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Posted 2007-June-22, 23:46
jdonn, on Jun 22 2007, 11:53 PM, said:
Aw don't stop, this has certainly been instructive for all of us!
OK, one last salvo then
p212 Roudinesco, combination 26b.
The proper play is exactly as I have stated and for exactly the reasons I have stated.
Restricted Choice doesn't enter into it.
I should probably write up a post on Restricted Choice just clean up cobwebs some might have on that topic...
#28
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Posted 2007-June-22, 23:56
That's probably a good idea.
Please let me know about any questions or interest or bug reports about GIB.
#29
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Posted 2007-June-23, 00:40
OK, finally you are starting to put up some actual stuff. Unfortunately, as I will show below, it still doesn't help you. Keep trying if you want, I'll keep knocking them down.
Yes, I agree that in these particular combinations, restricted choice does not apply. That is because all the relevant honors are non-touching, there are no relevant touching/equal honors where a defender has a choice of which to play & can randomize.
However, these combinations do not bear close resemblance to the suit combo being discussed. In the previous discussion, you have a non-touching honor, the K, and two touching honors, the JT. Restricted choice absolutely does apply to the probability of someone holding both the J & T. You seem to think that just because one of the honors is non-touching, restricted choice goes completely out the window. It doesn't, if there are still relevant touching honors. If you are looking for an example from the encyclopedia, look at the combination immediately preceding this section, under "other card combinations"
KT9 opposite 432.
Note that the best play is to hook low twice. Here, you have the ace missing, which is non-touching, and the QJ, which are touching. If restricted choice did NOT apply, it would be a tossup whether to play K or T 2nd round. But it does apply, because if RHO has both QJ he should play one or the other half the time, while with just one he will play it all the time.
This combo is analogous to the one under discussion, with the ace taking the role of the K, the QJ taking the role of the JT.
Note also that this example clearly breaks your previously posted bogus rules about restricted choice:
Yet somehow the encyclopedia still calls it a restricted choice situation ...
Please answer this. Set aside the line of playing Ace 2nd round temporarily. Do you, or do you not believe, that playing low 2nd round is better than the Q? And if so, how do you reconcile with the 3.4% vs. 2.8% chances you respectively assigned JT tight, stiff T, as I pointed out above?
These holdings are irrelevant as you always lose 2-3 tricks. The only relevant one here is JT doubleton. With the JT doubleton, the defender DOES have reason to randomize.
For the question of whether hooking low or the Q is better, you CAN pick. Deciding vs. playing the ace is somewhat different, just you have to assign probabilities to the falsecarding possibilities, and can't use 50% since there is no reason for the defender to use that unlike the equal honors case.
I'm not using any impossibilities. Just there are multiple ways to frame the argument. I am fine with ignoring J stiff since the problem specified RHO played the T. Just answer my questions above, explain why you get 3.4% for the frequency of JT doubleton.
I agree completely with Roudinesco here, and it's the answer I & others like Justin have stated all along. Against LHO who can't falsecard, play ace, against ones that can, hook low. The point of the matter, is that if you agree with this as I do, that hooking low is better than hooking Q, you are using restricted choice whether you know it or want to admit to it or not. If restricted choice was bogus, then hooking the Q would be arguably better than hooking low, since probability of JT is > than probability of stiff T. But it's not bogus, and you have to multiply that probability of JT by half before comparing to be correct. That's applying restricted choice.
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bottom p382 "a mistake to avoid" to top p383 Ex 4 and 5
(ex 4 is KJ9+xxx; ex 5 is AQTxxx+xxx)
(ex 4 is KJ9+xxx; ex 5 is AQTxxx+xxx)
Yes, I agree that in these particular combinations, restricted choice does not apply. That is because all the relevant honors are non-touching, there are no relevant touching/equal honors where a defender has a choice of which to play & can randomize.
However, these combinations do not bear close resemblance to the suit combo being discussed. In the previous discussion, you have a non-touching honor, the K, and two touching honors, the JT. Restricted choice absolutely does apply to the probability of someone holding both the J & T. You seem to think that just because one of the honors is non-touching, restricted choice goes completely out the window. It doesn't, if there are still relevant touching honors. If you are looking for an example from the encyclopedia, look at the combination immediately preceding this section, under "other card combinations"
KT9 opposite 432.
Note that the best play is to hook low twice. Here, you have the ace missing, which is non-touching, and the QJ, which are touching. If restricted choice did NOT apply, it would be a tossup whether to play K or T 2nd round. But it does apply, because if RHO has both QJ he should play one or the other half the time, while with just one he will play it all the time.
This combo is analogous to the one under discussion, with the ace taking the role of the K, the QJ taking the role of the JT.
Note also that this example clearly breaks your previously posted bogus rules about restricted choice:
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=you are missing 3 important cards, not 2 @ T1 in this suit.
=the 2 honors that remain missing are not neighbors in the suit (AK, KQ, QJ, JT)
=the 2 honors that remain missing are not neighbors in the suit (AK, KQ, QJ, JT)
Yet somehow the encyclopedia still calls it a restricted choice situation ...
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The odds do not change enough based on the play of T1 for it to affect your plans
Please answer this. Set aside the line of playing Ace 2nd round temporarily. Do you, or do you not believe, that playing low 2nd round is better than the Q? And if so, how do you reconcile with the 3.4% vs. 2.8% chances you respectively assigned JT tight, stiff T, as I pointed out above?
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Had the cards been 54+KJT, or x+KJTx would RHO =ever= win T1 with anything but the T?
No. He has no reason to randomize his choice or to falsecard.
No. He has no reason to randomize his choice or to falsecard.
These holdings are irrelevant as you always lose 2-3 tricks. The only relevant one here is JT doubleton. With the JT doubleton, the defender DOES have reason to randomize.
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If Restricted Choice held, you would be able to pick which card to play on T2 based on the play of T1 to maximize your chances. You can not. Therefore it is not an issue.
For the question of whether hooking low or the Q is better, you CAN pick. Deciding vs. playing the ace is somewhat different, just you have to assign probabilities to the falsecarding possibilities, and can't use 50% since there is no reason for the defender to use that unlike the equal honors case.
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..and using impossiblities as "props" for your arguments is such a logical fallacy as to make logical discussion of any topic that you bring them to impossible.
I'm not using any impossibilities. Just there are multiple ways to frame the argument. I am fine with ignoring J stiff since the problem specified RHO played the T. Just answer my questions above, explain why you get 3.4% for the frequency of JT doubleton.
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212 Roudinesco, combination 26b.
The proper play is exactly as I have stated and for exactly the reasons I have stated.
The proper play is exactly as I have stated and for exactly the reasons I have stated.
I agree completely with Roudinesco here, and it's the answer I & others like Justin have stated all along. Against LHO who can't falsecard, play ace, against ones that can, hook low. The point of the matter, is that if you agree with this as I do, that hooking low is better than hooking Q, you are using restricted choice whether you know it or want to admit to it or not. If restricted choice was bogus, then hooking the Q would be arguably better than hooking low, since probability of JT is > than probability of stiff T. But it's not bogus, and you have to multiply that probability of JT by half before comparing to be correct. That's applying restricted choice.
#30 Guest_Jlall_*
Posted 2007-June-23, 02:26
At some point you gotta ask yourself what is the point stephen 
#31
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Posted 2007-June-23, 04:24
Suitplay says the best play is to finesse twice small.
=> What is the use for LHO to falsecard with Jxx on the second round? If he play the J then you best play is still to play the Q loosing to the K, but you would have lost to the K anyway if you finesse twice small?
=> What is the use for LHO to falsecard with Jxx on the second round? If he play the J then you best play is still to play the Q loosing to the K, but you would have lost to the K anyway if you finesse twice small?
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#32
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Posted 2007-June-23, 09:11
kgr, on Jun 23 2007, 04:24 AM, said:
Suitplay says the best play is to finesse twice small.
=> What is the use for LHO to falsecard with Jxx on the second round? If he play the J then you best play is still to play the Q loosing to the K, but you would have lost to the K anyway if you finesse twice small?
=> What is the use for LHO to falsecard with Jxx on the second round? If he play the J then you best play is still to play the Q loosing to the K, but you would have lost to the K anyway if you finesse twice small?
But if you know that LHO never falsecards with Jxx, and RHO doesn't often falsecard with KT, then you would play the A, dropping the king.
The easiest way to count losers is to line up the people who talk about loser count, and count them. -Kieran Dyke
#33
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Posted 2007-June-23, 09:29
cherdano, on Jun 23 2007, 10:11 AM, said:
kgr, on Jun 23 2007, 04:24 AM, said:
Suitplay says the best play is to finesse twice small.
=> What is the use for LHO to falsecard with Jxx on the second round? If he play the J then you best play is still to play the Q loosing to the K, but you would have lost to the K anyway if you finesse twice small?
=> What is the use for LHO to falsecard with Jxx on the second round? If he play the J then you best play is still to play the Q loosing to the K, but you would have lost to the K anyway if you finesse twice small?
But if you know that LHO never falsecards with Jxx, and RHO doesn't often falsecard with KT, then you would play the A, dropping the king.
I bet if I falsecarded king declarer would be the doofus in the room who holds Jxx
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#34
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Posted 2007-June-23, 09:55
I have thought a bit about this Jxx falsecard. I think the basic reason is this: Sometimes lho is dealt JTx or JTxx. If he plays low first round the 8 or 9 will force the king after which declarer will pick up his JT (by force in the 3-2 case and by running the 9 or 8 in the 4-1 case). Therefore lho wishes to split with this JTx(x) holding. But if he only splits when holding both J and T, it won't work since the remaining honor is picked up on a finesse. So he "splits" when he holds Jxx or Txx as well.
Thus, the J or T from Jxx or Txx allows a split from JTx(x) w/o giving the show away. Whether it will work is another question. That is, if the first round goes spot JQK, how should declarer continue given that lho may or may not have the ten to go with his J?
If lho can be trusted to hop up with the J with or without the ten, it does give something away. After spot-spot-9-T and then spot-spot on the second round, declarer can rule out lho holding Jxx. This means there is no point in playing the ace second round, and the Q everyone seems to agree is clearly wrong, so lho is helpless when he is dealt KJxx. Paradoxically, perhaps, declarer has a tougher choice playing against, say, me. Or at least against me before I read this thread. I can't be trusted to hop up with the J first round, and so on the second round declarer has a real choice between playing low and playing the ace.
Of course no real paradox exists. Good defense makes it harder for declarer when lho holds one of Jxx, Txx, JTx(x) and these are the more frequent situations. He has to pay off when he holds KJxx or KTxx but it's not a huge deal since declarer had a good chance of getting it right anyway.
I hope this is not garbage or brain dead or whatever. It's an interesting combo.
Thus, the J or T from Jxx or Txx allows a split from JTx(x) w/o giving the show away. Whether it will work is another question. That is, if the first round goes spot JQK, how should declarer continue given that lho may or may not have the ten to go with his J?
If lho can be trusted to hop up with the J with or without the ten, it does give something away. After spot-spot-9-T and then spot-spot on the second round, declarer can rule out lho holding Jxx. This means there is no point in playing the ace second round, and the Q everyone seems to agree is clearly wrong, so lho is helpless when he is dealt KJxx. Paradoxically, perhaps, declarer has a tougher choice playing against, say, me. Or at least against me before I read this thread. I can't be trusted to hop up with the J first round, and so on the second round declarer has a real choice between playing low and playing the ace.
Of course no real paradox exists. Good defense makes it harder for declarer when lho holds one of Jxx, Txx, JTx(x) and these are the more frequent situations. He has to pay off when he holds KJxx or KTxx but it's not a huge deal since declarer had a good chance of getting it right anyway.
I hope this is not garbage or brain dead or whatever. It's an interesting combo.
Ken
#35
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Posted 2007-June-23, 10:50
No kenberg, the 2nd round falsecard is not at all about protecting JTxx/JTx. Declarer is supposed to pick up those combinations anyway; he will finesse 2nd round after it goes TQK o JQK. If he doesn't, he is giving up too much since those combos outnumber Jxx/Txx.
The falsecard is solely about protecting partner's KT, stopping declarer from dropping the K under the ace. If you falsecard, declarer still must finesse, since otherwise he'll lose to KJx which outnumbers Jxx. So it's a mandatory falsecard if you know the combo. The falsecard means that the best declarer can do is pick up KJxx. By falsecarding, defender is giving up KJxx to guarantee success on the more numerous Jxx. Declarer has no counter because KJx is still possible.
Although you could falsecard first round if you knew declarer held this combo, it's dangerous. Sometimes declarer has a 9 cd trump suit. He was planning to take MP line for max tricks, hook first round Q, then try to drop your J, losing 2 tricks on this layout with partner's stiff K. Falsecarding 2nd round doesn't have this problem.
.
Yes, if the goal is max exploitation. Declarer could always just decline to play ace 2nd round and guarantee the normal rate of success against good players, giving up the chance to gain 1.1% vs. ones that don't know to falsecard.
The falsecard is solely about protecting partner's KT, stopping declarer from dropping the K under the ace. If you falsecard, declarer still must finesse, since otherwise he'll lose to KJx which outnumbers Jxx. So it's a mandatory falsecard if you know the combo. The falsecard means that the best declarer can do is pick up KJxx. By falsecarding, defender is giving up KJxx to guarantee success on the more numerous Jxx. Declarer has no counter because KJx is still possible.
Although you could falsecard first round if you knew declarer held this combo, it's dangerous. Sometimes declarer has a 9 cd trump suit. He was planning to take MP line for max tricks, hook first round Q, then try to drop your J, losing 2 tricks on this layout with partner's stiff K. Falsecarding 2nd round doesn't have this problem.
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Paradoxically, perhaps, declarer has a tougher choice playing against, say, me
Yes, if the goal is max exploitation. Declarer could always just decline to play ace 2nd round and guarantee the normal rate of success against good players, giving up the chance to gain 1.1% vs. ones that don't know to falsecard.
#36
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Posted 2007-June-23, 14:39
I meant first round.
But anyway, even if defender is sure that declarer has exactly three cards (often he will be) I guess, as you say, he cannot save his JTx. If defender is known to throw the J/T on the first round from Jxx or Txx, then declarer might have a tense moment on the second round worrying whether the J was from Jxx or JTx but he will presumably count out the possibilities and then, I think, finesse.
But if this is so (as I think it is) then the first round falsecard is another way to get two defensive tricks when holding Jxx or Txx opposite KT or KJ. Given confidence in declarer's length, it should work.
But fundamentally I now agree, you are right. It's a second round play. Actually I think I would be up for the second round falsecard. It's almost obvious, really. But maybe I'll try it first round (the play I though was being suggested) sometime just for the excitement. As a practical matter it could be worth a trick or two later as declarer fumes.
Thanks for the response.
But anyway, even if defender is sure that declarer has exactly three cards (often he will be) I guess, as you say, he cannot save his JTx. If defender is known to throw the J/T on the first round from Jxx or Txx, then declarer might have a tense moment on the second round worrying whether the J was from Jxx or JTx but he will presumably count out the possibilities and then, I think, finesse.
But if this is so (as I think it is) then the first round falsecard is another way to get two defensive tricks when holding Jxx or Txx opposite KT or KJ. Given confidence in declarer's length, it should work.
But fundamentally I now agree, you are right. It's a second round play. Actually I think I would be up for the second round falsecard. It's almost obvious, really. But maybe I'll try it first round (the play I though was being suggested) sometime just for the excitement. As a practical matter it could be worth a trick or two later as declarer fumes.
Thanks for the response.
Ken
#37
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Posted 2007-June-23, 19:23
Stephen Tu, on Jun 23 2007, 06:50 PM, said:
The falsecard is solely about protecting partner's KT, stopping declarer from dropping the K under the ace. If you falsecard, declarer still must finesse, since otherwise he'll lose to KJx which outnumbers Jxx. So it's a mandatory falsecard if you know the combo. The falsecard means that the best declarer can do is pick up KJxx. By falsecarding, defender is giving up KJxx to guarantee success on the more numerous Jxx. Declarer has no counter because KJx is still possible.
You loose first finesse to the T:
- Playing the Ace is better when playing against opps that never falsecard with Jxx or Txx?
- Finessing with Q is better against opps that falsecard and play J or T second round (as he could have started from KJx or Jxx). I would think that KJx is as likely as Jxx?
- If a falsecarding opp plays x in the 2nd round, then you know he does not have Jxx. He can still have started from xx, Kxx, or KJxx. I would think that Kxx is more likely then KJxx and that finesse with the Q should be better then with the 9?
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#38
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Posted 2007-June-23, 19:37
kgr, on Jun 23 2007, 07:23 PM, said:
Stephen Tu, on Jun 23 2007, 06:50 PM, said:
The falsecard is solely about protecting partner's KT, stopping declarer from dropping the K under the ace. If you falsecard, declarer still must finesse, since otherwise he'll lose to KJx which outnumbers Jxx. So it's a mandatory falsecard if you know the combo. The falsecard means that the best declarer can do is pick up KJxx. By falsecarding, defender is giving up KJxx to guarantee success on the more numerous Jxx. Declarer has no counter because KJx is still possible.
You loose first finesse to the T:
- Playing the Ace is better when playing against opps that never falsecard with Jxx or Txx?
Yes.
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- Finessing with Q is better against opps that falsecard and play J or T second round (as he could have started from KJx or Jxx). I would think that KJx is as likely as Jxx?
Yes. No, KJx (two possible holdings) is more likely than Jxx (exactly one holding).
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- If a falsecarding opp plays x in the 2nd round, then you know he does not have Jxx. He can still have started from xx, Kxx, or KJxx. I would think that Kxx is more likely then KJxx and that finesse with the Q should be better then with the 9?
Kxx is slightly more likely than KJxx a priori; but due to restricted choice, after the first round to the ten, KJxx is almost twice as likely. (I hope foo doesn't read this because I don't want to see more nonsense in this thread.)
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#39
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Posted 2007-June-23, 22:15
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You loose first finesse to the T:
FYI, there is only one 'o' in "lose", "loser", "losing", opposite of win/winner/winning. Loose is a different word, opposite of "tight".
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-I would think that Kxx is more likely then KJxx and that finesse with the Q should be better then with the 9?
There are two valid ways you can think about this.
Remember that a priori, JT is 3.4%, stiff T is 2.8%
1:
The opponent shouldn't play T from JT all the time. So when you see the T, out of the combinations that matter here when comparing finesse lines, it is either he holds stiff T (2.8%), or he held JT AND he chose to play the T (3.4% * n=amount he doesn't falsecard). The opp is suppose to falsecard enough such that 3.4*n < 2.8, and also 3.4 * (1-n) < 2.8 (so that you don't have a tell when the J falls either). n = 0.5 = 50% is a reasonable estimate.
2:
Instead of just considering when the T falls on the right, also consider when the J falls on the right. If you treat both honors as the same, then finessing with the 9 if either falls picks up KJxx & KTxx (2.8 x 2 = 5.6%), while playing the Q picks up 3.4%, regardless of how often opponent is playing one card or the other from JT. 5.6 > 3.4 so ...
You can improve on this if the opponent from JT plays too often one card or the other AND you know what the tendency is, but if he keeps frequencies in the optimal range you can do no better than pick up the stiff honor combos.
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Posted 2007-June-24, 04:16
Tx Cherdano and Stephen (and all others) for these interesting answers. This is the first time I try to analyse a suit combination like this. (Trying to lose 
less in the future.).
Maybe this will be the start to analyse and understand others in the future.
Let me add some questions/remarks (with the help of suitplay):
1. After you played small to 9 and T, you play another small and LHO plays small. Following possible initial combinations are left:
a- xx vs KJT: 3.4 (not important, always loses 2)
b- Jxx vs KT: 3.4
c- Kxx vs JT: 3.4
d- KJxx vs T: 2.8
=>
- Play 8: 2.8 (picks d)
- Play Q: 3.4 (picks c); but this is actually only 1.7 as RHO would play the J half of the time.
- Play A: 3.4 (picks b )
==> Play the Ace is best (1b- )
2. Opps will always play J from Jxx in the 2nd trick.
Now option 1b- is no longer possible and it is better to play the 8 (==> 1d- )
3. Opps will play 50% of the time J from Jxx in the 2nd trick.
option 1d- is still better as probability of 1b- is only 50% of 3.4. (==> 1d- ). Sorry to ask this
: Do you consider this a restricted choice?
Questions:
A. The play against opps that don't falsecard feels very strange. First you take the deep finesse and then you play the Ace. I would then think it's better to play Ace the first trick and play small to the Q in the 2nd trick.
B. How is suitplay taking (or not) taking these falsecards and restricted choices into account? Seems like suitplay also prefers line 1d- (finesse twice deep). It also considers that with Jxx you can play as well twice small, as 1st small and then J?
C. I wonder how WC players do this at the table. They will only get this right if they studied the combo in advance?
Thanks again!
Koen
less in the future.).Maybe this will be the start to analyse and understand others in the future.
Let me add some questions/remarks (with the help of suitplay):
1. After you played small to 9 and T, you play another small and LHO plays small. Following possible initial combinations are left:
a- xx vs KJT: 3.4 (not important, always loses 2)
b- Jxx vs KT: 3.4
c- Kxx vs JT: 3.4
d- KJxx vs T: 2.8
=>
- Play 8: 2.8 (picks d)
- Play Q: 3.4 (picks c); but this is actually only 1.7 as RHO would play the J half of the time.
- Play A: 3.4 (picks b )
==> Play the Ace is best (1b- )
2. Opps will always play J from Jxx in the 2nd trick.
Now option 1b- is no longer possible and it is better to play the 8 (==> 1d- )
3. Opps will play 50% of the time J from Jxx in the 2nd trick.
option 1d- is still better as probability of 1b- is only 50% of 3.4. (==> 1d- ). Sorry to ask this
: Do you consider this a restricted choice?Questions:
A. The play against opps that don't falsecard feels very strange. First you take the deep finesse and then you play the Ace. I would then think it's better to play Ace the first trick and play small to the Q in the 2nd trick.
B. How is suitplay taking (or not) taking these falsecards and restricted choices into account? Seems like suitplay also prefers line 1d- (finesse twice deep). It also considers that with Jxx you can play as well twice small, as 1st small and then J?
C. I wonder how WC players do this at the table. They will only get this right if they studied the combo in advance?
Thanks again!
Koen
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