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Check my working Intra finesse?

#1 User is offline   Wackojack 

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Posted 2015-September-19, 05:10

♠ Q3
♥ K986
♦ A1053
♣ AK3





♠ A98654
♥ Q72
♦ --
♣ 9842


You are in South in 4♠. West leads 2♦. You ruff in hand. How do you maximise the chances of limiting your trump losses to one? EW are not strong players.

Play the 9 (or 8?) initially. If West plays low you assume that west would have played the King from Kx. Do you run the 9 or play the Q?

West East Combs Number of losing tricks by: Advantage
Run 9 Play Q Run 9 Play Q
Kxx JT 1 2 1 1
Jx KTx 2 1 2 2
Tx KJx 2 1 2 2
JT Kxx 1 NA NA
KJx Tx 2 2 1 2
KTx Jx 2 2 1 2
Jxx KT 1 2 2
Txx KJ 1 2 2
JTx Kx 2 1 2 2

This says that the number of combinations favouring the intra finesse = 6 against playing the Q =5. Am I correct?

Sorry this did not come out as a table as I intended.
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#2 User is offline   Fluffy 

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Posted 2015-September-19, 06:49

I didn't check your math but I recomend you start by trying to ruff a club in dummy. Low spade to the queen is better on 4-1 breaks with a stiff intermediate honnor which you didn't account.
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#3 User is offline   gszes 

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Posted 2015-September-19, 11:25

Dummy has a ton of entries and, unless declarer has good reason to assume you have the K, the play of the 9 pretty much has to be an intra finesse. That means you should duck with KJ KT Kx or Kx under the theory it gives your side a chance for 2 spade tricks vs 1 (since you will score the K when they run the Q). Rising with the K is a bad mistake since it almost invariably leads to only 1 spade trick while ducking will still net 1 and maybe 2. The point is that this is a bad hand to try an intrafinesse in general. Even if you are CERTAIN lho will rise with the K with any K(x) it is probably still better (fluffy) to just hope spades break 32 and try and ruff a club hoping to lose 1h 2s:) Having a tool is useful just make sure you apply it under the right circumstances:))
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#4 User is offline   Wackojack 

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Posted 2015-September-19, 17:13

View Postgszes, on 2015-September-19, 11:25, said:

Even if you are CERTAIN lho will rise with the K with any K(x) it is probably still better (fluffy) to just hope spades break 32 and try and ruff a club hoping to lose 1h 2s:) Having a tool is useful just make sure you apply it under the right circumstances:))


Cmon if you plan to ruff a club then you will lose 2 spades a club and a heart. The point is that I did say that East West were not strong players. So if west ducked any spade smoothly, then I am CERTAIN she would not have Kx, unless she was completely asleep. Yes chances of making this contract look slim but you have to try. All I am trying to ascertain is that based on the CERTAINTY that West would not duck from Kx, then which play gives me best odds?

My working says intra finesse. Am I right? This is not a rheotorical question. I am genuinely seeking expert opinion on this.
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#5 User is offline   WesleyC 

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Posted 2015-September-19, 23:07

Checking the maths of this situation is pretty easy using an Online Suit Combination Calculator.

In this scenario I would input the missing cards in the form: KHHxx (because the JT are equivalent).

Assuming LHO plays small, the gain cases for the intra-finesse is

LHO: Hx RHO: KHx (13.5%)
LHO: HHx RHO: kx (6.8%)

and the loss cases are:

LHO: Kx RHO: HHx (6.8%)
LHO: Kxx RHO: HH (3.4%)
LHO: KHx RHO: Hx (13.5%)

However, LHO should always split holding HHx so I wouldn't include that as a gain case.
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#6 User is offline   Wackojack 

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Posted 2015-September-21, 03:59

Thanks for that Wesley. I conclude that the intrafinesse gives slightly better odds of success when you are reasonably certain that west will play the King with Kx. At the table the intra did not occur to me so it went 42QK. Down!
West had J2, J1053, K762, Q76. East had: K107, A4, QJ984, J105. So the intra would have worked and with east having Ax, I could have made this poor contract.
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#7 User is offline   gszes 

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Posted 2015-September-21, 17:06

View PostWackojack, on 2015-September-19, 17:13, said:

Cmon if you plan to ruff a club then you will lose 2 spades a club and a heart. The point is that I did say that East West were not strong players. So if west ducked any spade smoothly, then I am CERTAIN she would not have Kx, unless she was completely asleep. Yes chances of making this contract look slim but you have to try. All I am trying to ascertain is that based on the CERTAINTY that West would not duck from Kx, then which play gives me best odds?

My working says intra finesse. Am I right? This is not a rheotorical question. I am genuinely seeking expert opinion on this.


SiGHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH my vision is really bad when the club THREE looks like the Q. My analysis (never expecting to lose a club) was totally stupid and based on misreading dummy's clubs. I agree if LHO would always rise with the K from any Kx then go with the intra finesse. Just as an aside next time rise with the dia A (pitching the heart 7) and lead a low heart toward Q (let me verify that spot) 2. You might be surprised how often rho will rise with the A and provide a parking place for your 4th club then the intra finesse has a much better chance of overall success of bringing the hand home:)
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#8 User is offline   phil_20686 

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Posted 2015-September-22, 01:43

I haven't looked at this hand closely but my instinct is that its better to try eloping with my trumps anyway. There are lots of variations. But I might try ruffing the opening lead playing the heart Q from hand. I might get a good read from this if lho isn't a strong player and ducks the ace here. If RHO wins the ace then I will almost always win as I get another dummy entry. If this holds I will play a club to the K and then ruff a diamond and a club to the ace and then a diamond ace, and discard a heart and play the 4th diamond. Now I can decide if I want to ruff this diamond or pitch my remaining heart. to transfer the ruff.

At any rate, at this point I will be set to score three red ruffs in the south hand, and if lho has only two clubs I doubt they can prevent me making this if I read the position right. Since I have scored 4 tricks and three ruffs, and so I need to arrange to score three more trump tricks with the position being, say,




and I exit a club. Now I like my odds (better). Depending what you want to do now. It seems a much stronger line than playing for Kx spade onside and 3-3 clubs, which is basically what your line amounts to. I mean, its hard to say what will happen, but suppose clubs are 3-3 and rho wins the club. What will they do now? if they play a spade, probably strongest, you can go up with the ace and ruff the 4th club with the Q and play a heart. playing lho for some 3343 including the spade K. If they are weak players they will not play a spade away from the K. If they are strong players maybe you just hope for whoever wins the club to have the spade K. then you can win the spade Q and then spade ace and the winning club.

If RHO has 4 clubs you are even better placed. LHO will be some 3442 most likely and then I will always make. If LHO is 4342 I might still struggle after a fourth club, as lho can pitch two hearts. Now I will need rho to have a stiff spade J or T. and exiting the spade Q will end play west.

Obviously things can go pretty wrong if lho has something like 3244, but you were probably struggling here anyway on your line.
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