He doesn't mention vulnerability, but it's IMPs so presumably the goal is to make your contract. West leads ♠K.
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#1
Posted 2011-February-03, 17:01
He doesn't mention vulnerability, but it's IMPs so presumably the goal is to make your contract. West leads ♠K.
#2
Posted 2011-February-06, 03:02
Judging from the book in question and the hour of the night my line is almost certainly not right.
#3
Posted 2011-February-07, 18:56
Mbodell, on 2011-February-06, 03:02, said:
Judging from the book in question and the hour of the night my line is almost certainly not right.
Hearts are 3-3, and after low to the ♦10, east exits in diamonds. Jack or small?
FWIW your line is the same as mine, so far. I don't think I cashed the fourth heart yet, but it shouldn't matter.
#4
Posted 2011-February-08, 01:48
JavaBean, on 2011-February-07, 18:56, said:
FWIW your line is the same as mine, so far. I don't think I cashed the fourth heart yet, but it shouldn't matter.
I originally wanted to say small because Hx opposite Hxxx is more likely than xx opposite HHxx. But it could also be x opposite HHxxx in which case J lets us win 2 ♦, 4♥, 1♠, 2♣. I'll try small. Unlucky?
#5
Posted 2011-February-08, 02:55
If the jack holds and west discards, we have to hope East has the ♣K and exit a diamond.
#6
Posted 2011-February-08, 03:54
#7
Posted 2011-February-08, 15:11
We "know" that West is 7=3 in the majors, so has three minor suit cards. The most likely distribution is for West to have one club and two diamonds, second most likely is two diamonds and one club. If West has two diamonds, the correct play, as noted above is low after the diamond ten loses as there are 10 ways West could have honor small in diamonds versus only six ways he could have small-small in diamonds.
The "solution" to this question is figure out the club distribution before you play on diamonds. On the last heart you pitch a diamond from dummy, what does East play? If it is diamond, expect diamonds to be 1=5 or 2=4, if it is a club, expect clubs to be 1= 4 or 0=5. The best line at this point is one that will help you figure out clubs before you play on diamonds. To do so, you can play on clubs now. On a club discard, lead a low club. If West plays the lowest outstanding club, play low. If West shows out, play low. If West plays any club but the lowest outstanding club, play the queen. Now you have an accurate diamond count (at least in theory). If West has a club, he would be 7=3=2=1, if he lacks a club, he would be 7=3=3=0. I think this is a 100% line after a club discard.
What if East discards a diamond? The solution is a lot trickier. I think you will be back to a guess. If West is 2=1 (most likely distribution), you will have to go with the percentage and duck the diamond return. If he is 1=2 you will have to play the diamond jack. East wins an honor and returns a diamond. What are the odds?
If West held just one diamond, it was low. There were C(4,1) or 4 ways he could hold a small diamond. If he held two diamonds, there are C(4,2) chances it was low (6 ways) but C(5,3) or 10 ways he could have held Hx. I am not sure if the calculations should reflect the low diamond East returns or the high diamond East won with. So I will leave those numbers. Since East threw a diamond, we assume he did not hold five clubs, so west will not be 3=0.\\
Playing Jack on East's diamond return wins when West held singleton small diamond (4 chances) or diamond low-low (6 chances). Playing low wins if West held high-low (10 chances). Are all these chances equally likely? The 2=4 diamond splits, yes. However, is West's minor suit holding 1=2 and 2=1 equally likely? The answer here is no. The 2=1 is more likely than the 1=2. So the chances for singleton small diamond is less likely than for any doubleton diamond. Without calculating the odds, this differences pushes me to play LOW on the diamond return. Still, it is almost essentially a guess (1=2 compared to 2=1 is about 4 to 5 ratio). I usually get these things wrong the first time, but that is my logic. 1) play on clubs if east discards a club, 2) play West for High-low doubleton diamond if East discards a diamond.
#8
Posted 2011-February-08, 20:24
inquiry, on 2011-February-08, 15:11, said:
Say West has Hx of diamonds and you play low. How do you make your contract? You've ducked a spade (1 loser), and then won the A. You've won 3 or 4 rounds of hearts, you've lost the ♦T to East (2 losers). If you play low and win the W ♦H with the A now what? If you play ♦J then ♣A then duck a ♣, East now wins a low ♣, K♣, 4th♦ and you are down. If you play ♦J and then duck a ♣, East can duck unless West has the smallest spot and now West runs spades.
Am I missing something, or does this mean we have to play the ♦J on the return.
Also, on the last heart (if we cash it) don't we have to pitch a club, not a diamond. We want to use the diamond to throw East in and/or as a possible winning trick if diamonds split 3-3.
#9
Posted 2011-February-08, 23:20
Mbodell, on 2011-February-08, 20:24, said:
Am I missing something, or does this mean we have to play the ♦J on the return.
Also, on the last heart (if we cash it) don't we have to pitch a club, not a diamond. We want to use the diamond to throw East in and/or as a possible winning trick if diamonds split 3-3.
You can discard a club or a diamond on the heart, it makes no difference. There maybe a psychological advantage to the club, as East with 4-4 in the minors might discard a club, which makes our life easier. But lets stick with the diamond discard for a moment, and ASSUME diamonds are 3-3 (your reason for keeping the 4th diamond). What will East discard? The assumption is a club. Now you lead a low club (as I stated) and West shows out. You duck in dummy in this ending (it doesn't matter if West holds a high diamond or not. Here I give him one) with East to lead, yoiu have lost two tricks and can lose two more... in ohter words you need four tricks.
Ok, having dealt with the fallicy of needing to save a diamond in case of a 3-3 diamond break, we can examine the earlier, point with West having High-low doubleton diamond. Here we assume East discarded a diamond, remember, if he discards a club, we play a small club -- NOT the diamond finesse)". That means in your analysis above he will not have a diamond to cash when he wins the low club. You said: "How do you make your contract? You've ducked a spade (1 loser), and then won the A. You've won 3 or 4 rounds of hearts, you've lost the ♦T to East (2 losers). If you play low and win the W ♦H with the A now what? If you play ♦J then ♣A then duck a ♣, East now wins a low ♣, K♣, 4th♦ and you are down. " You see, that "4th diamond" you have him cashing is not available if he discarded a diamond on the 4th heart. Of course if he was 4=4 in the minors and discarded a club, we play as above, planning on losing two clubs and a diamond while keeping West off the lead.
#10
Posted 2011-February-09, 20:58
To make the hand, you NEED east to hold the club King and at least one of the top diamonds, so we might as well assign those cards to East. That leaves four "small" clubs and five "other diamonds" including the second high one. So after you discover West has 7♠ and 3♥, that means he has 3 potential slots for the these 9 cards, and East has six potential slots for them. Let's consider for a second, these nine cards as a single suit. How can they be split?
West can have C(9,3) different holdings, and East C(9,6) different holdings. Either way, this comes to 84 possible holdings where game can be made C(9,3) which is 84 equal possibilities. As a check, we can test the following... #3=0 means west has 3 diamonds and no clubs, etc.
#3=0 is C(5,3) * C(4,0) = 10 * 1 = 10 combinations
#2=1 is C(5,2) * C(4,1) = 10 * 4 = 40 combinations
#1=2 is C(5,1) * C(4,2) = 5 * 6 = 30 combinations
#0=3 is C(5,0) * C(4,2) = 1 * 4 = 4 combinations
Total combinations are 84.
Ok, we have eliminated some of these. When EAST doesn't discard a club, we can eliminate West is void in clubs (losing 10 of the 84) and when we lead a low diamond and West DOES NOT play a diamond honor, we lose five of the 30 combinations (the one with a stiff diamond honor) from the 2=1 split and all of the 0-3 splits. So the corrected numbers are now....
#3=0 is ZERO combinations
#2-1 is still 40 combinations
#1-2 is reduced to 25 combinations
#0-3 is ZERO combinations.
NEW total is 65
Of the 25 remaining #1=2 splits, you have to play a diamond when East wins the diamond honor and returns a diamond. Of the 40 splits with 2 diamonds and 1 club with west, we have to determine the frequency of Honor-low versus low-low. Remember, already of the 65 possible hands, 25 require the play of the jack on a low !D back. If the 10 to 6 for High-low still exist in diamonds (and I think it doesn;t) that would make 15 times playing the JACK is right and 25 times, playing low is right. But 15+25 (1=2, and low-low=stiff) is greater than 25. So it looks like playing the JACK is right after all.
The reason I said it doesn't is I already forced one high diamond in East, so there is only one high diamonds (unknown) left out. Perhaps it is best to use C(4:1) for the low diamond (high low) and C(4:2) for low-low. I am not sure, but if so, then it is wayyyyyyy more likely that the both high diamonds are with East. I think I might be overthinking this one now.

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