[Cascade]

KQ109xx

xx

What is the best play ?

I am getting myself confused.

Fred says lead to the King and then to the Queen in one of the BridgeMaster deals. This concurs with SuitPlay but Rudinesco seems to say finesse the ten then the nine.

Anyway I am now officially confused and any help would be appreciated.

Thanks

[Sigi_BC84]

I haven't calculated it myself, but if we can trust Suitplay not to emit wrong figures (which would mean that its programmer has made serious mistakes) then I would say: go with Suitplay. Fred being of the same opinion should only reconfirm you in that decision.

There should be no reason to be confused in my eyes.

--Sigi

[whereagles]

From this odds calculator, you get

Roudinesco: wins 48%
Suitplay: wins 53%

(You can check it out yourself by ticking boxes along the three columns to the right.)

However, I know Roudinesco is a very careful person. I can hardly believe he made a mistake here.. Are you sure you were looking for in the right place?

[Cascade]

whereagles, on Mar 17 2006, 11:12 PM, said:

From this odds calculator, you get

Roudinesco: wins 48%
Suitplay: wins 53%

(You can check it out yourself by ticking boxes along the three columns to the right.)

However, I know Roudinesco is a very careful person. I can hardly believe he made a mistake here.. Are you sure you were looking for in the right place?

Chapter 11 (25) b pg 310

xx

KQ109xx

...

MAX and N 4 ... (1/2) Finesse the nine and ten.

[42]

playing low to KQ (if successful --> )

AJxxx .... ---
AJxx ...... x speaks for an immediate finesse
Axxx ..... J
AJx ..... xx
Axx..... Jx
AJ..... xxx
Ax ..... Jxx
A ..... Jxxx
Jxxx..... A speaks for an immediate finesse
Jxx ..... Ax
Jx ..... Axx
J ..... Axxx
xxx ..... AJ
xx ..... AJx
x ..... AJxx
--- ..... AJxxx

Did I forget or overlook something? So it looks as if one can play either way: 8 , 8

[Chamaco]

42, on Mar 17 2006, 12:07 PM, said:

Jxx ..... Ax

This layout would be picked up by the 2nd round finesse (low to the T), which I believe (correct me if wrong) is the % followup if the K loses to the Ace offside.

[hatchett]

Quote

This layout would be picked up by the 2nd round finesse (low to the T), which I believe (correct me if wrong) is the % followup if the K loses to the Ace offside.

But RHO might duck the Ace on the first round....

[Chamaco]

hatchett, on Mar 17 2006, 02:26 PM, said:

Quote

This layout would be picked up by the 2nd round finesse (low to the T), which I believe (correct me if wrong) is the % followup if the K loses to the Ace offside.

But RHO might duck the Ace on the first round....

Of course.
this would not be the first nor the last time one pays off to a falsecard.

Having said that, I think the option of RHO falsecarding does not change the fact that - theoretically - it is slightly the better % to play low to the K and if it loses, low to the T at second round.

This, from the theoretical viewpoint; but lots of better players than myself have commented on the role of "table feel", which is often used by experts when two lines' percentages differ by very little.

Nonetheless, this thread was - I think - on the *theoretical* analysis of this card combo.

[whereagles]

Cascade, on Mar 17 2006, 11:14 AM, said:

whereagles, on Mar 17 2006, 11:12 PM, said:

From this odds calculator, you get

Roudinesco: wins 48%
Suitplay: wins 53%

(You can check it out yourself by ticking boxes along the three columns to the right.)

However, I know Roudinesco is a very careful person. I can hardly believe he made a mistake here.. Are you sure you were looking for in the right place?

Chapter 11 (25) b pg 310

xx

KQ109xx

...

MAX and N 4 ... (1/2) Finesse the nine and ten.

Weird.. well, I dunno. Maybe you can send him an email

[Blofeld]

Finessing the ten and then the nine definitely looks better needing 4 tricks, and feels wrong needing 5 - could they both be right for different problems?

[Fluffy]

Chamaco, on Mar 17 2006, 02:31 PM, said:

Having said that, I think the option of RHO falsecarding does not change the fact that - theoretically - it is slightly the better % to play low to the K and if it loses, low to the T at second round.

I think we have talked about a similar suit before, and it was said that a perfect defender would win ♠K only on 2 cases: bare A, and AJ bare, then playing low to the Q even if it losed is still better.

[hatchett]

Quote

Having said that, I think the option of RHO falsecarding does not change the fact that - theoretically - it is slightly the better % to play low to the K and if it loses, low to the T at second round.

I'm not sure I'd call ducking the King with Ax a falsecard; but anyway, if you finesse on the second round after the ace is taken you lose to AJ.
Of course it depends how often RHO wins the A from Ax. I think to calculate the correct theoritical line you have to assume an optimal strategy by the defence.

[cherdano]

42, on Mar 17 2006, 02:07 PM, said:

playing low to KQ (if successful --> )

AJxxx .... ---
AJxx ...... x speaks for an immediate finesse
Axxx ..... J
AJx ..... xx
(...)
Did I forget or overlook something? So it looks as if one can play either way: 8 , 8

Caren, you missed two things: You should compare this list with the list of successes of the direct finesse. Also, some of these layouts are really several layouts, because there are several ways the small cards can be distributed. So it go s.th. like this:

AJxxx ... --
AJxx ... x (3 layouts)
etc.

Arend

[hatchett]

Quote

Did I forget or overlook something? So it looks as if one can play either way

42 Not all your combinations have equal probability

for instance AJxx x is more likely than Axxx J and so on

[Chamaco]

Fluffy, on Mar 17 2006, 02:52 PM, said:

Chamaco, on Mar 17 2006, 02:31 PM, said:

Having said that, I think the option of RHO falsecarding does not change the fact that - theoretically -  it is slightly the better % to play  low to the K and if it loses, low to the T at second round.

I think we have talked about a similar suit before, and it was said that a perfect defender would win ♠K only on 2 cases: bare A, and AJ bare, then playing low to the Q even if it losed is still better.

Hmm, sounds weird.

It i true that a good defender will very often not cover, but:

a. at least the same amount of time, he won't cover just because he does not have the Ace LOL (see restricted choices)

b. in many cases when he could cover but it not covering would be better, taking the suit in isolation, he might have other reasons to get in quickly and open a sidesuit.
Yes, this falls otside of the "theoretical analysis" in isolation, but still,, it seems to me that - despite the fact that RHO playing low does not guarantee he does not have the Ace - there will be > 50% chances that he indeed won't have it.

Indeed, the reason of many defensive falsecards is to induce declarer to play according to the % play
But the fact that a falsecard is possible does not mean - IMO - that we shuld refrain from making the % play (unless "table feel" comes into play): that would be equivalent to bidding weird in eeach and every boeard just for fear of a psyche LOL

Just thinking aloud, actually I'll be happy to change my mind and learn something from this :-)

[hatchett]

Quote

Fred says lead to the King and then to the Queen in one of the BridgeMaster deals. This concurs with SuitPlay but Rudinesco seems to say finesse the ten then the nine.

I have looked at Roudinesco and he does not say this! He says finesse the 10 and 9 if the hand under the KQT9xx is presumed to have length. With no length presumption Roudinesco starts off with low to the K and his next play if it wins depends on who you think the strong side is.

[joshs]

I think I am missing something in this thread. If the suit is 3-3, both plays are equally likely to succeed (assuming the ace is always ducked). If the suit is 4-2 you can pick up Jx in either hand by playing to the K and Q, but can only pick up Ax offside when playing to the T9. again this assumes best defense of always ducking the ace at the first trick.

Hence, playing to the KQ picks up one more case.

[cherdano]

joshs, on Mar 17 2006, 06:50 PM, said:

I think I am missing something in this thread. If the suit is 3-3, both plays are equally likely to succeed (assuming the ace is always ducked). If the suit is 4-2 you can pick up Jx in either hand by playing to the K and Q, but can only pick up Ax offside when playing to the T9. again this assumes best defense of always ducking the ace at the first trick.

Hence, playing to the KQ picks up one more case.

Director!
For your convenience, the hands were xx opposite KQT9xx.

[JohnnyH7]

http://forums.bridgebase.com/index.php?sho...mbination&st=30 is where this suit combination was discussed last.

[42]

Quote

Caren, you missed two things: You should compare this list with the list of successes of the direct finesse. Also, some of these layouts are really several layouts, because there are several ways the small cards can be distributed.
Arend

UAAAAARRRGGHHHHHHHHH That drives me crazy, I know again why I am only secretary for and no mathematician myself....
For the small cards: why do they matter since I cover them all? With both honors at least third behind or 1 honor fourth I cannot do anything but losing 2 tricks, independent of the small cards, or? I thought before if I should make 3 sad smilies for AJxx ... x but thought it doesnt matter. And wouldn't I have to make a third list with mixed strategy (the example that Mauro gave: with Jxx ... Ax first low to KQ, then low to 109)? If I edit my list how you said it is correct (or how I understood your hint), does it then look like this?

(2 times low to KQ / 2 times low to 109 / 1. low to KQ, 2. low to 109 )

AJxxx .... --- (1-/1-/1-)
AJxx ...... x (3-/3+/3-)
Axxx ..... J (1+/1-/1+)
AJx ..... xx (3+/3+/3+)
Axx..... Jx (3+/3-/3-)
AJ..... xxx (1+/0/0) low to the 10 might have been the will *hehe* No error possible
Ax ..... Jxx (3+/3-/3-)
A ..... Jxxx (1-/1-/1-)
Jxxx..... A (1-/1+/1-)
Jxx ..... Ax (3-/3+/3+)"mixed strategy" good if defender ducks the A first
Jx ..... Axx (3+/3+/0) mixed strategy impossible
J ..... Axxx (1+/0/0) no error possible
xxx ..... AJ (1+/1-/1-)
xx ..... AJx (3-/3-/3-)
x ..... AJxx (3-/3-/3-)
--- ..... AJxxx (1-/1-/1-)

Now I count:
16+ : 16- for low to KQ
13+ : 17- against low to 109
7+ : 20- against mixed strategy

The winner is: low to KQ!
I am really excited now LOL

Is this calculation ok this way?????
Can anyone figure that out at the table?