[kgr]

Scoring: IMP

1H-2H
4H
(2H=3-card and 7+)

---

Lead is small ♦ for ♦A of East.
Small ♣ returned for ♣T and ♣J and West plays another ♣ for ♣K and your A.
You now play ♥K and East plays ♥J. You know that Opps are not good enough to play ♥J from ♥JTx (probability is 5%). RHO has either ♥J or ♥JT.
What is best play now?
1) Is restircted choice enough reason for ♥ finesse?
2) Does elimination possiblity increases the chanches enough for the finesse?

This post has been edited by kgr: 2008-November-29, 20:05

[Rossoneri]

Am I missing something? Why can't you play small to the A♥ next and see if West started with JT bare?

[kgr]

Rossoneri, on Nov 30 2008, 03:59 AM, said:

Am I missing something? Why can't you play small to the A♥ next and see if West started with JT bare?

I corrected the post. RHO played the ♥J

[awm]

Restricted choice always applies in these sorts of situations. East is twice as likely to hold singleton jack as to hold JT-tight. If these are the only two possibilities then you should finesse.

[Cascade]

The odds are:

Stiff Jack
5C1*21C12/26C13/5 = 2.8%

The Jack is always played from Stiff Jack - 2.8%

Doubleton Jack-Ten

5C2*21C11/26C13/5C2 = 3.4%

The Jack is played somewhere between 0% and 100%. This combination will be less likely than the stiff Jack if the Jack is played less often than 2.8/3.4 = 83.3%.


Jack-Ten-x

(5C3*21C10/26C13)*(3/10) = 10.2%

This combination will be less likely than stiff Jack if the Jack is played less than 2.8/10.2 = 27.8%. (Given the false card can be with the jack or the ten this is equivalent to a false card about 55.6% of the time if the jack and ten false cards are equally likely).

All of this suggests that you should false card often with J10x.

If you do not then declarer should use restricted choice arguments to finesse against your partner's ten.

With J10 we need to mix up the card we have played. A player that always plays the Jack or the Ten is too predictable.

[awm]

Cascade, on Nov 30 2008, 01:07 AM, said:

All of this suggests that you should false card often with J10x.

If you do not then declarer should use restricted choice arguments to finesse against your partner's ten.

With J10 we need to mix up the card we have played. A player that always plays the Jack or the Ten is too predictable.

While this is all true in principle, it's not clear how much it matters at the table.

It is sometimes more important what declarer thinks we will do. In many cases we have not defended enough hands against this declarer that he will know a whole lot about our tendencies. For example, suppose I always play the jack from JT. Will declarer catch on? If he hasn't played a few hundred boards against me, probably not.

On the other hand, declarer might tend to assume that I'm not likely to falsecard from JTx until proven otherwise, in which case falsecarding is an even bigger win.

[jdonn]

awm, on Nov 30 2008, 01:35 AM, said:

Cascade, on Nov 30 2008, 01:07 AM, said:

All of this suggests that you should false card often with J10x.

If you do not then declarer should use restricted choice arguments to finesse against your partner's ten.

With J10 we need to mix up the card we have played.  A player that always plays the Jack or the Ten is too predictable.

While this is all true in principle, it's not clear how much it matters at the table.

It is sometimes more important what declarer thinks we will do. In many cases we have not defended enough hands against this declarer that he will know a whole lot about our tendencies. For example, suppose I always play the jack from JT. Will declarer catch on? If he hasn't played a few hundred boards against me, probably not.

On the other hand, declarer might tend to assume that I'm not likely to falsecard from JTx until proven otherwise, in which case falsecarding is an even bigger win.

Not to mention, I think I can pick it out correctly based purely on tempo and how they play the card over 80% of the time at the table against less than expert competition.

[kgr]

Thanks for the answers so far! really appreciated!

---

When the ♥K is played, RHO does not know what declarer has. The suit could be distributed as above. Then flasecarding could give away a trick.
...So you can assume that RHO will only falsecarding occasionaly and therefor you best play him for ♥J single?
...If you plan to finesse in ♥ is it better to eliminate ♦ and ♣ first (RHO already showed ♣K, ♥J and ♦A, ♠K would give him 11HCP and maybe he would have found a bid over 2♥ then. Does you 'feel' that probabilityof RHO having ♠K compensate ruff risk?)

[kgr]

awm, on Nov 30 2008, 05:25 AM, said:

Restricted choice always applies in these sorts of situations. East is twice as likely to hold singleton jack as to hold JT-tight. If these are the only two possibilities then you should finesse.

Thank you, interesting; but I verified with suitplay and it is not completely true (..as far as I understand this).
AKQ987
vs
32
 
Probability of RHO holding
JTx : 10.2%
JT: 3.4%
If RHO plays the J under your A then :
Probability of RHO was holding initially:
JTx : 5.1% (assuming RHO often falsecards, half of 10.2%)
JT: 3.4%
=> So you should still play from top....In practice you probably should finesse here against most players.

[gwnn]

kgr, on Nov 30 2008, 01:23 PM, said:

Thanks for the answers so far! really appreciated!

---

When the ♥K is played, RHO does not know what declarer has. The suit could be distributed as above. Then flasecarding could give away a trick.
...So you can assume that RHO will only falsecarding occasionaly and therefor you best play him for ♥J single?
...If you plan to finesse in ♥ is it better to eliminate ♦ and ♣ first (RHO already showed ♣K, ♥J and ♦A, ♠K would give him 11HCP and maybe he would have found a bid over 2♥ then. Does you 'feel' that probabilityof RHO having ♠K compensate ruff risk?)

umm, where is the trump queen?

[kgr]

gwnn, on Nov 30 2008, 01:45 PM, said:

kgr, on Nov 30 2008, 01:23 PM, said:

Thanks for the answers so far! really appreciated!

Axx x JTx K98xxx

When the ♥K is played, RHO does not know what declarer has. The suit could be distributed as above. Then flasecarding could give away a trick.
...So you can assume that RHO will only falsecarding occasionaly and therefor you best play him for ♥J single?
...If you plan to finesse in ♥ is it better to eliminate ♦ and ♣ first (RHO already showed ♣K, ♥J and ♦A, ♠K would give him 11HCP and maybe he would have found a bid over 2♥ then. Does you 'feel' that probabilityof RHO having ♠K compensate ruff risk?)

umm, where is the trump queen?

Ok, did not make a lot of sense if bridge is played with a Q in every suit

[matmat]

kgr, on Nov 30 2008, 06:34 AM, said:

awm, on Nov 30 2008, 05:25 AM, said:

Restricted choice always applies in these sorts of situations. East is twice as likely to hold singleton jack as to hold JT-tight. If these are the only two possibilities then you should finesse.

Thank you, interesting; but I verified with suitplay and it is not completely true (..as far as I understand this).
AKQ987
vs
32
 
Probability of RHO holding
JTx : 10.2%
JT: 3.4%
If RHO plays the J under your A then :
Probability of RHO was holding initially:
JTx : 5.1% (assuming RHO often falsecards, half of 10.2%)
JT: 3.4%
=> So you should still play from top....In practice you probably should finesse here against most players.

which part of " If these are the only two possibilities then you should finesse " is so difficult to understand?!

in your "verification," and I use the term very loosely, you introduced a third case (JTx), completely ignored the case of the stiff honor, and forgot to adjust your percentages for J only being played roughly half the time from JT. You also ignored the case of JTxx where RHO might be trying to get you to waste an entry to hand to finesse.

[gwnn]

Koen, why don't you reread this older thread of yours?

[jdonn]

I loved rereading that old thread. I miss foo.

[MarkDean]

That other thread made me so amused and depressed at the same time.

[MarkDean]

Here is a variation on restricted choice/falsecarding.

You are in a diamond contract, and just need to pull trump successfully to make it.

Dummy has: K762
You have AQT5

You play the ace, LHO plays the 9, and RHO plays the 8. Which way do you play the suit?

[awm]

MarkDean, on Nov 30 2008, 03:52 PM, said:

Here is a variation on restricted choice/falsecarding.

You are in a diamond contract, and just need to pull trump successfully to make it.

Dummy has: K762
You have AQT5

You play the ace, LHO plays the 9, and RHO plays the 8. Which way do you play the suit?

It seems strange not to play king next. If the suit divides J9xx -- 8 then LHO could have always defeated you by simply hanging on to the nine. There is no particular reason for him to play the nine here, he can see the dummy and knows he is risking a natural trump trick.

On the other hand, if the suit divides 9 -- J8xx then RHO knows you will pick up his jack by playing normally, and it is no cost to play the eight and give you a losing alternate line.

[kgr]

matmat, on Nov 30 2008, 08:54 PM, said:

kgr, on Nov 30 2008, 06:34 AM, said:

awm, on Nov 30 2008, 05:25 AM, said:

Restricted choice always applies in these sorts of situations. East is twice as likely to hold singleton jack as to hold JT-tight. If these are the only two possibilities then you should finesse.

Thank you, interesting; but I verified with suitplay and it is not completely true (..as far as I understand this).
AKQ987
vs
32
 
Probability of RHO holding
JTx : 10.2%
JT: 3.4%
If RHO plays the J under your A then :
Probability of RHO was holding initially:
JTx : 5.1% (assuming RHO often falsecards, half of 10.2%)
JT: 3.4%
=> So you should still play from top....In practice you probably should finesse here against most players.

which part of " If these are the only two possibilities then you should finesse " is so difficult to understand?!

in your "verification," and I use the term very loosely, you introduced a third case (JTx), completely ignored the case of the stiff honor, and forgot to adjust your percentages for J only being played roughly half the time from JT. You also ignored the case of JTxx where RHO might be trying to get you to waste an entry to hand to finesse.

I don't know what I was telling here. Doesn't seem to make sense. Sorry for that!