Guest Jlall Posted October 22, 2006 Report Share Posted October 22, 2006 You are playing imps and have AK987x of spades, 322. It goes 1N p 3N p p p and its your lead. Do you lead a high one or a low one? Thx. Quote Link to comment Share on other sites More sharing options...
hrothgar Posted October 22, 2006 Report Share Posted October 22, 2006 AKT98x would have been a lot easier... I'm going to lead low here (I would have lead the 10 off the first) Quote Link to comment Share on other sites More sharing options...
mikeh Posted October 23, 2006 Report Share Posted October 23, 2006 I've always led low from these holdings, but (even tho I will still lead low here) I am increasingly finding that I am losing imps by doing so: lost a game swing in Verona for example... the opps led high and ran the suit. Was that just bad luck? I like to think so :) Quote Link to comment Share on other sites More sharing options...
Winstonm Posted October 23, 2006 Report Share Posted October 23, 2006 Isn't the only relevant holdings 322 - if one of the opps held a singleton spade they might have looked for a suit contract, and if partner is stiff then the suit won't run and I'm entryless - so it seems that low should be best as I'm bucking 2/1 odds with 1 partner and 2 opponents that my partner has the 3-card holding. The other question is do they have 8 fast tricks outside my suit? The only time it is right to lead low is when partner has xx (forgetting Qx for this debate) and an entry to stop their 8 trick run; but leading high only wins whenever partner is dealt xxx. A last concern is when partner has Qx, or QJ and the high-card lead blocks the suit. It seems not too close to me - low - when the suit is right to lead - has to be the favorite. Quote Link to comment Share on other sites More sharing options...
the hog Posted October 23, 2006 Report Share Posted October 23, 2006 Lead low. Better than leading an hon, finding pd with xx in S and an entry and the suit distributed 3-2. Try explaining that to him and you won't get much sympathy Quote Link to comment Share on other sites More sharing options...
Guest Jlall Posted October 23, 2006 Report Share Posted October 23, 2006 so it seems that low should be best as I'm bucking 2/1 odds with 1 partner and 2 opponents that my partner has the 3-card holding. There are some flaws in this argument... First of all, there may be other defenses to beat the contract. Leading high and finding a killing shift is possible. Secondly, if you can run the suit immediately, you will certainly beat the contract. However even if you catch partner with a doubleton (which you rate to do when the suit is 322 as you say) you still havent beaten it yet. A lot of the time the opponents will just run 9 tricks. Leading low even if you catch partner with a doubleton you still need him to have an entry and enough stoppers to stop the opponents from running the suit (unless his doubleton is Qx). I would bet that you will not beat the contract half the time that you find the suit 322 with partner having 2 anyways which would mean leading high is more likely to beat the contract. Quote Link to comment Share on other sites More sharing options...
cherdano Posted October 23, 2006 Report Share Posted October 23, 2006 Let's assume the suit is 6322. Leading high wins immediately when partner has 3, which is happens 1/3 of the time, or when the 3-card suit only has low ones, which adds another 9%. Leading low wins immediately when partner has the queen, which a priori happens about 1/3 of the time. Plus probably when partner has the Jack but not the ten, and LHO the queen, which happens 7.4% of the time according to my calculations. So the chances to beat it directly are pretty similar - except for the problem that partner is less likely to hold the queen than opps, who have some 26-31 hcp. So the problem is whether we make up for this deficit by the chance that partner has a doubleton and an entry before they take 8 tricks in the other 3 suits. E.g. if we think partner has the queen 20% of the time, then it would be enough if we beat it 25% of the time partner has a low doubleton. It seems to me the best chances to beat it via the spade suit is a low one. How good is the additional chance to beat it by leading high and finding a shift? Pretty low for such a hcp auction I would think, but it might become more attractive when it is clear that they are bidding 3N on a running suit and little outside. Arend Quote Link to comment Share on other sites More sharing options...
the hog Posted October 23, 2006 Report Share Posted October 23, 2006 so it seems that low should be best as I'm bucking 2/1 odds with 1 partner and 2 opponents that my partner has the 3-card holding. There are some flaws in this argument... First of all, there may be other defenses to beat the contract. Leading high and finding a killing shift is possible. Secondly, if you can run the suit immediately, you will certainly beat the contract. However even if you catch partner with a doubleton (which you rate to do when the suit is 322 as you say) you still havent beaten it yet. A lot of the time the opponents will just run 9 tricks. Leading low even if you catch partner with a doubleton you still need him to have an entry and enough stoppers to stop the opponents from running the suit (unless his doubleton is Qx). I would bet that you will not beat the contract half the time that you find the suit 322 with partner having 2 anyways which would mean leading high is more likely to beat the contract. Hmm. Interesting.Ben, would you be prepared to do some of your thorough research on this? I, for one, would be very interested in the results. Quote Link to comment Share on other sites More sharing options...
cherdano Posted October 23, 2006 Report Share Posted October 23, 2006 AKT98x would have been a lot easier... I'm going to lead low here (I would have lead the 10 off the first) I don't understand your reasoning here. Leading high from AKT98x works more often, as it is more likely that the 3-card suit can't stop us at trick 3. (Assuming 6322 split, the total a priori chances are 51% instead of 42%.) Arend Quote Link to comment Share on other sites More sharing options...
Guest Jlall Posted October 23, 2006 Report Share Posted October 23, 2006 This situation seems like the perfect candidate for simulation and it happens quite often. As the early results here indicate, I think more experts lead low than high, but as you might have figured out I have always been in the high camp. I would really like some conclusive data one way or the other. Quote Link to comment Share on other sites More sharing options...
Flame Posted October 23, 2006 Report Share Posted October 23, 2006 I dont know the answer (i tend to lead small) but i think there are factors that matter. First is entry to your hand, if you think you got an entry like having something good in a short suit then leading high is more likely to be better.Second is whather its a major or minor suit, after 1NT-3NT its more likely to find the opponenets 2=2 in a major then in a minor, so a major high is more likely to work then a minor high. Quote Link to comment Share on other sites More sharing options...
Echognome Posted October 23, 2006 Report Share Posted October 23, 2006 I have given this problem some thought theoretically and my conclusion is that it's very complicated. We have two major unknown subjective probabilities to deal with. First off is the probability that if we lead high and we need to switch that we find it. The second probability that is unknown is if we blow a trick at trick 1 that they do not have 8 other tricks. That is to say, we may be giving them their 9th trick at trick 1. Whatever weights you give to these unknown probabilities will have a big effect on any conclusions we draw. Looking at some specific holdings around the spade suit when we lead low: 6=2=3=2 (that is 6 for opening leader, 2 for dummy, 3 for partner, and 2 for declarer). If say that an upper bound for the location of the Q in partner's hand are the vacant spaces (I believe it's less), then 4/7 of the time we are blowing a trick at trick one. And probably getting a surprised declarer when he wins the first trick with Qx opposite Jx or xx. 6=2=2=3. In 2/7 of the cases, we set outright. (again an upper bound) In the other 5/7 of the cases, we only set when they don't have 8 other tricks. We also may have blown a trick when partner has JT or when partner has Jx and declarer has to guess, albeit this is unlikely. However, if there is Qx in dummy and Txx in declarer's hand we may set a cold contract. 6=3=2=2. In 2/7 of the cases, we set outright. In the other cases we may put declarer to a guess (Qxx opposite Tx) and we may cost a trick outright (xxx opposite Qx). 6=3=1=3. In almost no case are we going to set. But we may be giving up a tempo. 6=2=1=4. We may be blowing a full trick here. In other cases, we are almost surely losing a tempo. Then again, when we lead high, we have to figure out whether to continue or switch and that seems like it could be complicated as well. I guess what I'm saying is that theory isn't going to take us very far. I imagine that simulation is the only real way to answer this question. Quote Link to comment Share on other sites More sharing options...
Halo Posted October 23, 2006 Report Share Posted October 23, 2006 It is true that opponents can have exactly eight tricks and partner have three solid tricks. But partner usually also needs a lower missing honour to stop oppos establishing a trick by force in the suit you led, and even that only helps half the time when the queen is under the AK. Of course partner may have three fast tricks, but that has to be unlikely on about 7-9 points It feels much more probable that opponents don't have eight quick tricks and have to concede one trick to partner. I would therefore lead small. Quote Link to comment Share on other sites More sharing options...
Finch Posted October 23, 2006 Report Share Posted October 23, 2006 I'm generally a low leader. To compare with mikeh's loss in Verona, I won a big swing recently from leading low when partner had Qx. We are looking only at the case where we don't have an outside entry, as of course we would have bid with an outside ace or king. I believe the chance of the suit being 6322 is lower than most people seem to be suggesting. Holding something like xAx(x)xxx(x)AQ10xxx(x) most people just raise 1NT to 3NT - particularly if to show a club suit they would have to bid 2S. Of course, a related upside to leading a top one is one dummy has a singleton honour and partner 10x. Quote Link to comment Share on other sites More sharing options...
kgr Posted October 23, 2006 Report Share Posted October 23, 2006 In Jack after 1NT-3NT with W:AK9875xxxxxxx=> 1000 samples:SA: -327.9SK: -352.9 (no idea why, maybe unblocking is expected/not expected)S5: -364.1S9,8,7: -388.2Hx: -494 Quote Link to comment Share on other sites More sharing options...
Guest Jlall Posted October 23, 2006 Report Share Posted October 23, 2006 interesting results from jack... can someone do a simulation with more hands than that? Quote Link to comment Share on other sites More sharing options...
Finch Posted October 23, 2006 Report Share Posted October 23, 2006 You'll have to specify the 3NT bid fairly carefully, not only to include all the balanced hands while excluding hands that would have looked for a heart fit; but to include unbalanced hands with a long minor that are both strong enough to want to punt 3NT but not strong enough to look for alternative contracts. And the exact specification of those hands depends on the opponents' methods. (For example, I play 1NT - 2S as a xfer to clubs, and 2NT as a xfer to diamonds. Opener is supposed to complete with Axx, Kxx or better. So you would make the xfer on a hand where that holding opposite tells you if the suit is running e.g. AQxxxx and, but you wouldn't bother xferring if that isn't what you are after (e.g. AKxxxx you just guess if the suit is running or not). I'm not trying to claim these are the best methods, but they affect what hands raise directly to 3NT. Also, because we use 2S as a club transfer, we aren't going to bother transferring on a marginal raise to 3NT with spade shortage to avoid getting doubled) Quote Link to comment Share on other sites More sharing options...
cherdano Posted October 23, 2006 Report Share Posted October 23, 2006 With 6331 shape and strong enough to bid 3N, I would usually transfer to my minor and then show my singleton at the 3-level. With 13(54) I would bid 3M. Both are not necessarily slam tries, but can just be choice of games. Is this non-standard? I would also like to know the exact specification of the Jack analysis. Was it double dummy? What is Jack's style for 1N-3N? Arend Quote Link to comment Share on other sites More sharing options...
gwnn Posted October 23, 2006 Report Share Posted October 23, 2006 4th best (no entry) Quote Link to comment Share on other sites More sharing options...
kenrexford Posted October 23, 2006 Report Share Posted October 23, 2006 I'd overcall 2♠ and save myself the grief. Quote Link to comment Share on other sites More sharing options...
whereagles Posted October 23, 2006 Report Share Posted October 23, 2006 Low seems best, but given it's a 6-carder, top is worth a thought. Definitely a long-sample simulation problem. By the way, it's not certain pard will know to unblock with all holdings, but I guess we can forget that in a 1st approximation.. lol. The way 3NT was bid might also be of interest. If 3NT was bid confidently, you might need a miracle to beat it and a top lead might just do it. If opps look ashamed with their bids, low might work better since opps overbid and won't run 9 tricks... lol :( Quote Link to comment Share on other sites More sharing options...
Winstonm Posted October 24, 2006 Report Share Posted October 24, 2006 Trying to guess whether dummy will come down with a singleton spade is somewhat of a waste of time - also, the times when it is right to switch will probably be washed out with the times it isn't along with the times it doesn't matter. What I want to do is defeat this contract when it is an ordinary contract and is beatable - and that means what is best when the suit divides 322. (And even if it is 6124, low may be necessary) If partner has 3 cards, then 3/7 ths of the time won't he also hold the Q?It would seem the only time it is right on combination to lead high is when partner has 3 cards not including the Queen. Isn't that 4/7 of the time he holds 3 cards? The loss of tempo is a consideration, but with AK to hope that partner has a holding nearly as good and and entry and I have to find the right switch seems somewhat of a stretch. (This could be more important in MPs where cherry picking our 3 tricks may be worth all the marbles). I am not a mathematician, but it seems to me of the critical holding 3-2-2, that only 4/7 of the tiimes that partner starts with 3 is a high card start necessary - in all other 3-2-2 holdings when the contract is beatable, low offers the best chance to beat the contract if leading my suit is right. And the other consideration is that low offers the best chance of a push, as I believe the majority would lead low from this holding. Quote Link to comment Share on other sites More sharing options...
cherdano Posted October 24, 2006 Report Share Posted October 24, 2006 I'd overcall 2♠ and save myself the grief. Then at least you could be sure that the suit is not 6421 with partner having the singleton, I agree. Quote Link to comment Share on other sites More sharing options...
Echognome Posted October 24, 2006 Report Share Posted October 24, 2006 If partner has 3 cards, then 3/7 ths of the time won't he also hold the Q?It would seem the only time it is right on combination to lead high is when partner has 3 cards not including the Queen. Isn't that 4/7 of the time he holds 3 cards? This is exactly the point. The least likely holding for partner is 3 cards. The second point is that partner will hold the Q less than 3/7 of the time he has 3. Why? Because opponents have the majority of the high cards based on their auction. What the actual probabilities are is rather difficult. But I think you are losing a tempo more often than you think. Quote Link to comment Share on other sites More sharing options...
kgr Posted October 24, 2006 Report Share Posted October 24, 2006 I did rerun the sample in Jack after 1NT-3NT with W:AK9875xxxxxxxFor the bidding system I defined SAYC. I suppose that Jack takes this into account when making the samples. => 1000 samples:SA: -344.8S8: -367.0SK: -369.8 (still no idea why, maybe unblocking is expected/not expected)S6,7,9: -392.0H3: -501.9In previous sample the bidding system was Berry for beginners. Seems like SAYC is more strict in leading 4th best.I thought that the samples were analysed Double dummy, but then there would be no difference in leading S8 or other Sx. Quote Link to comment Share on other sites More sharing options...
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