PhilKing

Simulation 2 was way in favour of the finesse, running off 6 anaswered winners at one point. Added to sim one the results are pretty close to the 57% (4/3) expected.

But the question is whether to finesse or play for the drop when second hand plays low on the third round - not whether to win the trick when he plays the jack.

Any tool that can reach a total chance of 116% for two almost mutually exclusive lines has my admiration. I don't think the chance of AQxxx xxx Jxx AK fully accounts for this, somehow. How it can then drop to a cumulative 90% shows a worrying drop in class. Did you program in that the non-leader followed to three diamonds? Anyway, I will do an extra simulation later today, fully expecting a result of 4/3 against, although it will not be for some time due to having just finished a monster poker session. B-)

This sounds pretty tight. I think I'd better run another simulation. :(

You can turn this on its head: Each specific 3 card club holding with the opening leader can be dealt 10 ways (ie the 10 xx combinations in diamonds). Each specific 2-card holding in clubs in the leader's hand can also be dealt ten ways (the 10 Jxx combinations). Anyway, on the off chance that this argument is gibberish, here's another: Things have changed from the time we knew it was 7-5 in favour of the non-leader having the diamond jack. 16 combinations have been eliminated from contention for the 7/5 guy having the diamond jack (jxx - 10, Jx - 5, J - 1) but ony six cases of the 5/7 guy holding that card can be discounted (Jx and J).

I decided it was time to "shut up and deal."(Well I managed the first part) I dealt 100 hands using the "vacant spaces" method. The 12 cards outside hearts and spades were dealt into two piles of seven and five cards to reflect the known 2-card disparity. Obviously, on a large number of the cases the diamond position is known before declarer plays to the the third diamond (the most common being when Jxx showed up onside which represents the silver bullet for the 7/5 theory) and these are represented with a dash. Here are the results: D = Drop, F = finesse, - = irrelevant -D-D--FF-D--D-FFF-FD-D-F--DF------DFDD-D----DF-F-D-D---FFDF--D---FDD-D-----DFFF---F---D-FF--F-D-FD--F Well done the finesse for an impressive late rush. Ok, that's not a huge sample, but it's now penalties in Spain Portugal. Anyway, that's 24/23 in favour of the finesse for 24 swings in of 12 imps and 23 losses of 13 imps against a "dropper".

This is certainly true. I tried it again with a One Spade overcall over One Club, just so Jack know the lead was not off a 3-carder and it came up with some absurd conclusions. Back to the card combibations, have you factored down the 4-2 diamond breaks to reflect that the diamond jack has not dropped (a priori 5 combinations)? There are, after all 10 ways for East to be dealt Jxx and 10 ways to be dealt xx, once the Jx's are removed. Since East's average holding in diamonds is 2.5 when he holds 8 cards in the major, it seems there is no need to weigh the holding one way or tother.

At the critical point you know that East has one of two distributions: 5323 5332 Both are equally likely, surely. After all you are missing six cards in each minor. The "vacant spaces" argument is a red herring, since you could equally well apply it to the club suit with an assertion such as: "East has 5 vacant spaces compared to West's 7, so is likely to be shorter in clubs. Therefore he is more likely to have the diamond." Doesn't wash, really, does it. Another way of looking at it is this: West either has four diamonds or he has four clubs. We know he is either 3343 or 3334. Explain to me why he is more likely to have four diamonds than four clubs. East has an average of 2.5 cards in each minor. Period. Finessing and going 2 down loses an extra imp. Assuming they play it differently in the other room you will lose 12 or gain 13 by playing for the drop.

It developed this way as a matter of chance. Originally, I played 2 split-range systems. The one you describe for teams events (with Steel and Rosen from about 1996) and another related system with Garvey and McIntosh from 1995 for pairs play. The Pairs system was slightly more off the wall: 1H/1S/1NT on all weak no trumps with a 1NT opening denying a major (cooperative double over interference after 1H/S/NT), 1C nat or 15-17 bal and 1d nat or 18-20 bal. Since it's obviously unplayable to play 1D 15-17 in case partner is inconsiderate enough to respond 1NT, the 1D response had to show the 18-20, and it seemed natural to retain this usage when playing the other system. As it happens, opening 1C on 12-14 balanced works very well with transfers, giving accuracy you simply can't achieve after opening 1D. After (say) 1c-1d(4+H) we now play 2H as a terrible raise (usually min weak NT with 4 or 5431 types with 11-13 and 3 card support. Responder can now snap-pass with 11 points and 4 hearts. Better raises bid 1H (many hand types) and then clarify on the next round: partner generally bids 1S (breakable puppet), then 1NT = 12-14 bal, 2D 14-16 unbal with 3H (5431 or 63, enabling responder to move aggressively with a club fit and 8+), 2H decent 4 card raise (over which responder drives game on any 11 or shapely 9+). So there are THREE ways of raising to 2H, thus little need to ever try for game at the three level.