correction of possible card distribution

[jahol]

Recently, my partner has the following "simple" problem:

 

imp SCORINGHe was playing 3NT having the following cards

 

 

----7---A62--8762--KQ542

 

K642--KQ5--KQ5---A109

 

after spade lead. Actually, he went three down and the result was -14IMP. On the first look, it seems to be impossible even for the "almost beginner" (my partner is well advanced bridge player). The problem was that he opened the bidding with one no thrumph after that LHO bid 2 diamonds - 6 cards in hearts or spades, preemptive (then my 3NT finished the auction). After that my partner decided to play RHO for fourth jack of clubs, but the jack was second in LHOs hand.

 

In my opinion, the fact that LHO has six cards in one major (spades probably) does not justify this play. It is not stupid mistake, but I think that the statistical adjustment is not strong enough to change the way of card play in this board that drastically.

 

What is your opinion?

[Free]

I don't see a real problem to make this contract... you play low ♠ 2 times, block the suit, and finesse ♣ to east (not west). If west has ♦A I'm screwed, otherwise I'll make my contract pretty comfortable.

[luis]

Jahol:

I think the fact that west showed a 6 card major doesn't make enough merit for a club finesse, I think it even increases the chances of clubs breaking! Why? See:

For a one-suited hand with a 6 card major West can have 6331 or 6322, there're 4 6331 distributions and 4 6322 distributions for a total of 8 only in 1 of 8 west has a singleton club, when he has a 6331 with just 1 club.

 

I think you should play the 3 heart tricks first, if west discards in the second or third round he is likley to be 6322 or 6331 and clubs break 3-2. If west follows to 3 rounds of hearts then it's still ok to play clubs from the top but if you play the finesse you will have some simpathy (not from me).

 

Finally:

 

Free, your line is ansolutely wrong, first of all no need to finesse in clubs and finessing to east, the player who is likely to be long doesn't make any sense at all. You are down if west has the dA with 9 top tricks. Makes no sense at all.

[Flame]

If you only ask about the club precentage i would probebly play like your partner, play the K of club first and then first finnese,

but on the all hand i think its better to duck a spade twice, then play clubs 3 tops this gives you some more chances when the clubs doesnt work if the diamonds A is with your RHO, i wouldnt however play the finnese like Free suggested, this is imo worse then your partner's line.

[inquiry]

I will not address whether ducking ♠ is right or wrong, but I probably would. I just want to address the issue of hooking club through EAST and whether or not this is a horrible play.

 

In isolation, the "correct" aka percentage play in the ♣ suit can be readily calculated. A five-0 split sort of does you in as you are only going to get 4♣ tricks, so you will need EAST to have the ♦ACE (hope in this case you infact did hold up on the ♠ suit.

 

With WEST having 6♠ to east's two, the odds of dropping the ♣J in three rounds (J, Jx, Jxx with either), is 69.5%. The hook of EAST for the ♣Jack is only 66.5% (and that includes teh 5-0 split which isn't that helpful, and with WEST having 6♠, odds of 5-0 is 5.4%, reducing the ♣ hook to 61.1%). So clearly hooking ♣ as your partner did appears wrong.

 

However, you partner could have done something before playing clubs. He could have played the two high ♥ from his hand. If both followed twice, there are now know 8 cards is WEST (6♠+2♥), versus 4 in east (2♥. 2[sp). Now the odds have increased nicely that the ♣ hook is the right play. In fact, before touching clubs, the odds of dropping ♣J, Jx, or Jxx has now decreased to... 66.8%. When both follow to the first round of ♣, what are the odds now? The odds of east having the long ♣ has gone up. Dropping ♣J odds in three rounds is only 66.4%, while odds of the club play finding the ♣J stiff or EAST with Jack long is up to 70.6%. But once again, a large percentage of those cases, EAST has Jxxxx and is useless to you, so the effective percentage drops to 64.2%, so once again playing for the drop is slightly better.

 

Ok, so you play a ♣ to dummy king and both follow. Now, know cards are 9WEST, 5EAST, and no one had singleton ♣J. What do the odds say hook versus play for drop? The hook is now right 66.7% of the time, while the odds for the drop actually have increased to 72% of the time.

 

So your partner's line is always slighly inferior to the "simple" line of cashing clubs.

 

FREE's line of ducking the first two spades, has a lot of merit. If they continue two more rounds of ♠, you are no worse off than you were if you won the first ♠. If they switch to a ♦, again you are no worse off, and if ♣ turn out bad for you, if EAST has ♦A as well as ♣, you can sometimes still come to 9 tricks in the form of 1♠+2♦+3♥+3♣

 

An easy way to play with the changing odds of different distributions as known lenght's are determined, see...

 

Distribution calculator

[luis]

I will not address whether ducking ♠ is right or wrong, but I probably would. I just want to address the issue of hooking club through EAST and whether or not this is a horrible play.

 

In isolation, the "correct" aka percentage play in the ♣ suit can be readily calculated. A five-0 split sort of does you in as you are only going to get 4♣ tricks, so you will need EAST to have the ♦ACE (hope in this case you infact did hold up on the ♠ suit.

 

With WEST having 6♠ to east's two, the odds of dropping the ♣J in three rounds (J, Jx, Jxx with either), is 69.5%. The hook of EAST for the ♣Jack is only 66.5% (and that includes teh 5-0 split which isn't that helpful, and with WEST having 6♠, odds of 5-0 is 5.4%, reducing the ♣ hook to 61.1%). So clearly hooking ♣ as your partner did appears wrong.

 

However, you partner could have done something before playing clubs. He could have played the two high ♥ from his hand. If both followed twice, there are now know 8 cards is WEST (6♠+2♥), versus 4 in east (2♥. 2[sp). Now the odds have increased nicely that the ♣ hook is the right play. In fact, before touching clubs, the odds of dropping ♣J, Jx, or Jxx has now decreased to... 66.8%. When both follow to the first round of ♣, what are the odds now? The odds of east having the long ♣ has gone up. Dropping ♣J odds in three rounds is only 66.4%, while odds of the club play finding the ♣J stiff or EAST with Jack long is up to 70.6%. But once again, a large percentage of those cases, EAST has Jxxxx and is useless to you, so the effective percentage drops to 64.2%, so once again playing for the drop is slightly better.

 

Ok, so you play a ♣ to dummy king and both follow. Now, know cards are 9WEST, 5EAST, and no one had singleton ♣J. What do the odds say hook versus play for drop? The hook is now right 66.7% of the time, while the odds for the drop actually have increased to 72% of the time.

 

So your partner's line is always slighly inferior to the "simple" line of cashing clubs.

 

FREE's line of ducking the first two spades, has a lot of merit. If they continue two more rounds of ♠, you are no worse off than you were if you won the first ♠. If they switch to a ♦, again you are no worse off, and if ♣ turn out bad for you, if EAST has ♦A as well as ♣, you can sometimes still come to 9 tricks in the form of 1♠+2♦+3♥+3♣

 

An easy way to play with the changing odds of different distributions as known lenght's are determined, see...

 

Distribution calculator

Ben I think all your calculations are wrong this time, West announced a 6 card major, they seem to be playing woolsey so he has a one suited hand with a 6 card major. So the only distributions to be considered are 6322 and 6331 the club finesse is 1 in 8.

If you play 3 hearts and west follows to the 3 rounds it's 1 in 3. If west discards in the 2nd or third round the club finesse is close to 0%.

[inquiry]

Well, if WEST can't have a side four card suit, and we believe that, of course it will affect the odds calculation. I went with WEST having a six card suit without regard to any other suit. ...

 

And the reason I cash two hearts in the above description, was it does change the odds.. Yes, if WEST has only one ♥, I would never, ever take the hook through EAST in ♣. But anyway, I was just addressing the ♣ suit is isolation, not how to play the hand per se.

 

Ben

[Flame]

Ben i think you have a principe mistake in there, this program cannot be use for this, and maybe its almost useless.

I must leave the comp now, but later i will explain with some example from a book by granoveter.

[inquiry]

Ben i think you have a principe mistake in there, this program cannot be use for this, and maybe its almost useless.

I must leave the comp now, but later i will explain with some example from a book by granoveter.

Well let's take an extreme example...

 

IF you are missing 8 ♦'s, what are the odds that there will be a singleton ♦ somewhere? With no other information, the odds look something like this....

 

East with singleton (7-1) about 1.4%

West with singleton (7-1) about 1.4%

 

For a total chance of singleton fo 2.8%

 

Now imagine WEST leads a club, EAST shows out, so you discover that WEST had WEST 10 known clubs. How does that affect the odds? Well, EAST can no longer have a singleton ♦, so the that is gone, but the chance WEST has a singleton ♦ has gone way, way up. It turns out that this is now 40%.

 

This program will help you figure this out, and of course, that is what it is designed for. What you can't do, of course, is muck around with nonspecific cards. Say in the example I gave earlier, East got a chance to discard a diamond on something. That no longer becomes a "known" card. As he has to play some card. So you can't dial in known cards at random. But if you know, WEST has 6♠ and thus east has two, you can dial those in. And if you know, both have two ♥, I believe you can dial those in as well (since they followed suit). But if you feel less than comfortable doing that, ok. What you can't do, is this. If East threw a heart somewhere on something (say a ♠) don't add a ♥ to his total. I only count cards they are forced to play or suits you can get accurate count on. But no matter how you do it, the ♣ hook was against the odds.

 

Ben

[Flame]

Ben i'll open a new thread b/c i think this might interest other members that already gave this thread up. unfortunetly I dont have the granoveters book with me here, but ill give my own example and try to explain.

[Cascade]

Given that the spades are 6-2 the odds for the club distribution are as follows I think:

 

5 0 0.00245098

4 1 0.044934641

3 2 0.224673203

2 3 0.404411765

1 4 0.269607843

0 5 0.053921569

 

With the first column being the number of clubs in the long spade hand.

[inquiry]

After thinking about htis hand, if Luis is right that 2♦ promises a six card suit with one suiter, the ♣ hook is 1) not necessary, and 2) should be taken with a sure win in adjustment.... when the hook loses... you call the director and say, I was given an inappropriate explaination. I would have NEVER hooked if WEST was sure to have 6322 distribution with any three card side suit. The hook would be stupid.

 

If indeed that is their agreement, you would get an adjustment (perhaps). Something to think about. Give accurate description of your agreements.

 

Ben