Trumpace

Thanks!

Hi BBO folks, The challenge a friend/stranger matches are a great feature! We plan to use this to organize a wimbledon like individual tournament. I am curious if there are any limits there and what they are. E.g: How many challenge matches per week/month can one play? Do the limits change if we paid for the bots? etc. Thanks!

If this was in a textbook, the answer would be to cash diamond AK before the fourth heart :D

Something like this is definitely playable. I first encountered it on pavlicek's site: http://www.rpbridge.net/7g19.htm#4 Seems a bit strange that no one seems to have mentioned this...

Perhaps this (cashing SA at trick 2) is an interesting deception opportunity for declarer holding Ax, A, AKxxx, KQxxx. btw, perhaps there is an additional (weak) inference (in support of club ruff) in declarer blasting to 5D (and going past 3NT)?

I was playing this Robot tournament: http://webutil.bridgebase.com/v2/tview.php?t=1105-1383259801 On this hand (UGH, the hand is inlined in unreadable font size. The hand is M-18413211-1383259801) http://www.bridgebase.com/tools/handviewer.html?myhand=M-18413211-1383259801 It seems like a double by the West GIB Robot was missed (based on what it did on other tables). The explanations for the subsequent bids seem consistent with a double being missed too. As a result, the East Robot was stuck (I guess you can call it a deadlock), and I could not complete the hand (and the tournament). This could potentially be a bug in the flash client/server infrastructure (and not the GIB robot per se), but I am reporting it here

I promised to keep my mouth shut, but... We cannot cater to clubs 3-3 as the club suit is blocked. 3rd heart ruffed, diamonds, which you ruff. Club won with K and another diamond. Now you are shut out from the 4th club. (I mentioned that earlier in some post, I guess it was easy to miss. Sorry). 4-2 hearts with long trumps having long hearts will give his partner 10 minor suit cards. Perhaps he would have bid something, or maybe not. "guarantee" is a strong word :) btw, the discussion was never about overtricks. I don't see anyone other than you talking about it :)

I think a club lead is very likely (which you don't seem be taking into account). So what you say does not convince me. Anyway... I guess broze must be uncomfortably brimming with pity by now, so I will shut up :)

Obviously. :) I am curious. The apriori probability is ~7% (with minor variations restricting diamond lengths with east/west). Are you thinking the fact that a club was the opening lead more than doubles that? What lead were you expecting?

Yes, restricted choice is what I was thinking when I was talking about chances of club lead _probably_ increasing chances of CK. It is your statement about a diamond lead being as likely as a club lead (from honour holding) and restricted choice which increases the chances of a club lead indicating a holding of CK. But there are other issues, like from DAxxx or DJxxx would LHO lead a diamond etc. I was not claiming it is overwhelming or anything, or even confident that it actually increases the chances of LHO holding CK. One could do the math by applying Bayes' formula and get an approximate figure, but that is not my point. All this calculation business was just to make the point that it is not clear cut to play the A, and I am pretty sure there is a lot not taken into account (some of which cannot be quantified even, and frankly I think trying to do all these computations is pointless at the table). I agree with the A play, not because it seems clear cut (or x% better), but because it seems to be the more flexible play: you stay alive longer if you run into bad breaks.

Yes. I am expecting a minor suit lead on this auction. To me a club lead tells me nothing extra about whether it is a singleton, but in fact seems to increase the chances that the opening leader holds the ♣K. To make it a B/N problem, without losing the point of the hand, just replace a heart spot with the Jack in the dummy. I think B/N problems should have a clear cut answer demonstrating the point of the hand.

Why? An attacking lead is called for. I would say that increases the chances of CK to your left doesn't it? btw, I didn't account for many factors... :-) All I was trying to say is that this forum is unsuitable for this problem.

Losing the club finesse still gives you that chance, doesn't it? If you don't run into a club ruff, you still have those chances. A different way to look at it: Say you have a trump loser for sure. Now playing the A vs the Q basically comes down to hearts 3-3 vs club finesse doesn't it? (You can't cater to 3-3 clubs in the CA line, as clubs will be blocked). Now you can factor in the chances of a club ruff and try to decide. (Of course, there are other factors like misdefence, other minor factors etc which complicates matters) Of course, playing the A seems to be the more flexible option, and if one cannot be bothered about the details, choosing the more flexible option tends to be correct.

I used pavlicek's calculators. I ignored the tendencies of the opp, conditional probabilities etc and went by pure apriori probabilities (i.e ignored a bad spade split affecting club split probabilities etc). btw, on this hand, isn't an attacking lead called for? After all, there was a 2H bid by dummy (and given the 3S bid, I presume 2H was game forcing, and dummy was fishing for slam). So underleading the CK is to be expected. To elaborate on the calculations: we split our calculation in three parts: 1) There is 79% chance that you can pick up the trumps. Playing the Q loses about 7.5% when you ruff into a club ruff, so that comes to ~5%. So playing the Q makes 74% of the time. 2) There is 17% chance that you have exactly one trump loser. Playing the Q wins if there is no club ruff and LHO has the CK, slightly less < 50%, so playing Q wins ~8%. 3) 4% of the time you have a 5-0 trump split. I am assuming you go down. So playing the Q wins roughly 82% of the time. Playing the A wins when trumps can be picked up(79%) or hearts divide 3-3 (in part 2 above), which is approx 6%. (You can't cater to clubs 3-3 as the club suit is blocked and you won't have entries to hand after CA, three rounds of trump, three round of hearts discarding a diamond, ruffed. A diamond comes back, ruffed, C to K, ruffed, and 4th club is cut off) So playing the A wins about 85% of the time.

I don't think this is the right forum for this problem. Give Dummy the heart J, then yes, probably. Even giving the Heart T, it might be a bit too much for this forum. There might be something obvious, but I find myself trying to do futile computations trying to decide which line is better (go up with CA or finesse on trick 1). It seems like playing the A might be better by about 3%, but don't take my word for it.