Miron Posted March 14, 2006 Report Share Posted March 14, 2006 [hv=n=sat62&w=s&e=s&s=sq853]399|300|[/hv] How to play this for just one looser (you need 3 spade tricks)? Quote Link to comment Share on other sites More sharing options...
Walddk Posted March 14, 2006 Report Share Posted March 14, 2006 Three reasonable lines: 1. Cash the ace and lead small to the queen.2. Lead a small to the queen, and if it loses, finesse the 10 next.3. Lead a small to the queen, and if it loses, cash the ace next. I believe that 1. is a little better and that the overall chance of success is around 50%. Roland Quote Link to comment Share on other sites More sharing options...
inquiry Posted March 14, 2006 Report Share Posted March 14, 2006 If you need three tricks, I agree with roland, cash the ACE and lead towards the Q. However, if the spade jack has not shown up, you have equal chances for three tricks by playing the Queen or ducking. Why? If West has KJ remaining, it doesn't matter what you play, and if East four with KJ it doesn't matter what you paly. So you are playing West for singleton king or singleton jack. I guess the odds of either or those is roughly (well exactly) equal if there is not any other clues from the bidding. Curious question is what happens if the nine show up from West under the Ace. Quote Link to comment Share on other sites More sharing options...
ArcLight Posted March 14, 2006 Report Share Posted March 14, 2006 I checked this in Suitplay and Roland and Ben are correct, Ace then low to Queen. Is there a way to see how much worse Rolands #2 and #3 are? >2. Lead a small to the queen, and if it loses, finesse the 10 next.>3. Lead a small to the queen, and if it loses, cash the ace next. Suit play allows one to save the results and probabilites, so it can be cut and pasted into Excel. Any other programs? Quote Link to comment Share on other sites More sharing options...
Miron Posted March 14, 2006 Author Report Share Posted March 14, 2006 For sure it is possible to enumerate all possibilities. But I'm bit lazy to do this. a) K9xx J has x%...i) fails at afg, successes at bckletc. I've done it for Q9xx A108xx, it took about 30 minutes. I think that here could be a known best cardplay. Few years ago I translated one such a article but this combination wasn't included. Quote Link to comment Share on other sites More sharing options...
joshs Posted March 14, 2006 Report Share Posted March 14, 2006 I just like the idea of picking up the stiff 9 on your left with "play the A" and then when you see the 9 run the ten. God gave you the 8,6,5 for a reason, right? Quote Link to comment Share on other sites More sharing options...
Al_U_Card Posted March 14, 2006 Report Share Posted March 14, 2006 God gave you the 8,6,5 for a reason, right? You must be playing in a pretty strong field.... :) Quote Link to comment Share on other sites More sharing options...
yapuka Posted March 14, 2006 Report Share Posted March 14, 2006 the overall chance of success is around 50% SuitPlay calculates a 58,782% chance of making 3 tricks with these cards. Quote Link to comment Share on other sites More sharing options...
kenberg Posted March 15, 2006 Report Share Posted March 15, 2006 I just like the idea of picking up the stiff 9 on your left with "play the A" and then when you see the 9 run the ten. God gave you the 8,6,5 for a reason, right? Following Joshs, I ask: Is the following correct? Suppose it begins A, small small, 9. You lead the ten and see small on your right, eliminating the possibility the 9 was false. If lho was dealt KJ9, it doesn't matter what you do. The remaining choices for original holding:K9J99 alone It appears that running the ten is a 2-1 odds on choice (of the times when it matters). Surprising (to me), but it seems right. Ken Quote Link to comment Share on other sites More sharing options...
Codo Posted March 15, 2006 Report Share Posted March 15, 2006 RHo LHO: KJ9 74K9 J74 J9 K749 KJ74 In the first case, it does not matter, in the 3. it looses to let the ten run.So if you are sure, that lho will show up with another Spade, letting the ten run will win. If leftly has just a singelton Spade, there is no way to succeed. Quote Link to comment Share on other sites More sharing options...
jillybean Posted March 15, 2006 Report Share Posted March 15, 2006 These are good and fun. I particularly appreciate the explanations on WHY it should be played a certain way. For anyone like me, still coming to grips with combinations there is this old thread with lots of examples. http://forums.bridgebase.com/index.php?act=ST&f=5&t=5151 jb Quote Link to comment Share on other sites More sharing options...
kenberg Posted March 15, 2006 Report Share Posted March 15, 2006 If lefty has only one spade, the ten will hold the trick, lho shows out, you lead small towards the Q. Assuming an entry to the board, it would not have helped rho to cover the ten since after lho shows out the finesse will be marked (small to Q8 if the T was covered with the K, small to the 8 if the play went T-J-Q -out). If the 9 was singleton, running the ten works fine. Only if the 9 was from J9 will running the ten be wrong (as always, assuming there is a right and wrong). On some layouts, a defender holding the J9 alone should falsecard with the Jack, but that would be a disaster here, as his only realistic chance for a trick is for declarer to run the ten to his Jack. Assuming this is right, as I think it is, I guess we can list the holdings where defenders will take two tricks when declarer starts with the A and then usually leads small to the Q but runs the ten if the 9 (or higher) falls fourth hand under the ace. KJx (three choices for x)KJxy(three choices for xy)KJxyz (one choice)Kx (where x<9, so two choices)J9x (where again x<9 so two choices)void I think this is the complete list, corrections welcome. There are 32 (=2^5) layouts for five cards so this leads to an estimate of 13/32 chances of failure, 19/32 chances of success. My calculator tells me that 19/32 is approximately .594 which is in pretty fair agreement with .588 reported by yapuka from cardplay. The 19/32 is not exactly correct because of "empty spaces". If you flipped a fair coin five times and asked for the probability of the result being from a stipulated list of 19 from the possible 32, the probability eould be exactly 19/32. With bridge hands you have to consider given five cards vwxyz that the specific lie vw-xyz is a bit more likely than the specific lie v-wxyz. This causes a slight shift when estimating probabilites, the most well-known example being that when holding 11 cards, the opposing cards split 1-1 slightly more than half the time, while if you flip a fair coin twice the probability of one head and one tail is exactly 50% (the 4=2^2 possible results, equally likely, are HH, HT, TH, TT). Ken Quote Link to comment Share on other sites More sharing options...
inquiry Posted March 15, 2006 Report Share Posted March 15, 2006 It appears that running the ten is a 2-1 odds on choice (of the times when it matters). Surprising (to me), but it seems right. Ken Which is why I raised this question in my earlier post, I found this option interesting. Curious question is what happens if the nine show up from West under the Ace. Quote Link to comment Share on other sites More sharing options...
kenberg Posted March 15, 2006 Report Share Posted March 15, 2006 It appears that running the ten is a 2-1 odds on choice (of the times when it matters). Surprising (to me), but it seems right. Ken Which is why I raised this question in my earlier post, I found this option interesting. Curious question is what happens if the nine show up from West under the Ace. Ah yes. Missed seeing your curious question. Apologies. K Quote Link to comment Share on other sites More sharing options...
inquiry Posted March 15, 2006 Report Share Posted March 15, 2006 Ah yes. Missed seeing your curious question. Apologies. K Np whatso ever.. was just an interesting twist I thought should be discussed since Roland (and I) answered the "major" question. In fact, I think the right answer (ACE first) is obvious, so this should have been the question. Good job finding it and getting it correct for the right reasons!!! Quote Link to comment Share on other sites More sharing options...
dcvetkov Posted March 15, 2006 Report Share Posted March 15, 2006 Three reasonable lines: 1. Cash the ace and lead small to the queen. This line may still be the best, but looks like it ignores the fact that you have 10 in one hand... There must be a way to mathematically quantify this difference. Actually, I happened to observe on lecture on BBO, and lecturer, recommended one different line not mentioned here Lead the Queen, and if it loses , or its covered, lead small to the 10 next. I am not sure this is superior or inferior to the first line though, Quote Link to comment Share on other sites More sharing options...
kenberg Posted March 16, 2006 Report Share Posted March 16, 2006 Three reasonable lines: 1. Cash the ace and lead small to the queen. This line may still be the best, but looks like it ignores the fact that you have 10 in one hand... There must be a way to mathematically quantify this difference. Actually, I happened to observe on lecture on BBO, and lecturer, recommended one different line not mentioned here Lead the Queen, and if it loses , or its covered, lead small to the 10 next. I am not sure this is superior or inferior to the first line though, Unless I counted wrong, there will be 17 ways for the cards to lie wrong in this approach. That would make this line slightly less than 50%.Here is my list: Any time the KJ is with East, including KJ tight since the plan is to play to the ten after the Q is taken by the King. There are eight of these. If the King is singleton with E, you also fail because after small to the ten you are outspotted (the J9 surrounds your 8). So there are 9 failures when the King is with E. When the King is with W, the Q will be covered, the ace taken, and after returning to hand a small is led towards the ten. The original holdings in the E hand for which this will fail are J9x (two of these)J9xy (one)Jx (with x<9) (two of these)x (with x<9) (two)void (again you are outspotted, even tho after trick one you will know the lie.) (one of these, of course) As the fine print always says, these calculations are believed accurate but not guaranteed. That adds to 17 making the estimate of failure 17/32, the estimate of success 15/32. Considerably worse than the liine endorsed by Walddk, Inquiry, etc, probably enoughof a difference to even absorb a small error in my thinking. Ken Quote Link to comment Share on other sites More sharing options...
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