[lamford]

Scoring: IMP

1NT - Pass - 3D - Pass
3NT - Pass - 4C - Pass
4D - Pass - 5D - All Pass

---

An interesting hand from the round of 16 of the Rosenblum. West, Martens, led ace, king and another club, East showing an even number. How would you play? In the other room, after a similar auction, Meckstroth led the ace, king and another club, East again showing two, so the same problem presents itself. Apologies if you have seen the hand.

[nigel_k]

Against most people, ruff with the ace and run the nine. Against good opponents, ruff low. The hard part is figuring out who counts as 'good', but Rodwell and whoever Martens was playing with would qualify.

[lamford]

Hamann played for Jassem, Martens' partner to have either given a false count signal, or to not have the jack of diamonds, and he ruffed low. Kopecky in the other room thought for a long time, and ruffed with the ace, successfully.

I think it is very close, as Hamann's line also fails when clubs are 3-3 and East has Jxxx in diamonds. If they will always find the false count signal, I think he is right.

[nigel_k]

lamford, on Oct 11 2010, 01:17 PM, said:

I think it is very close, as Hamann's line also fails when clubs are 3-3 and East has Jxxx in diamonds. If they will always find the false count signal, I think he is right.

You might still succeed in this case but will need spades 3-3 or the ten dropping as you would have to use ♥A to shorten your trumps.

[ceeb]

nigel_k, on Oct 10 2010, 07:48 PM, said:

lamford, on Oct 11 2010, 01:17 PM, said:

I think it is very close, as Hamann's line also fails when clubs are 3-3 and East has Jxxx in diamonds. If they will always find the false count signal, I think he is right.

You might still succeed in this case but will need spades 3-3 or the ten dropping as you would have to use ♥A to shorten your trumps.

Alternatively Hamman might have been planning, if RHO followed to the 3rd club, to cash ♦K, and if all follow low unblock the ♠KJ immediately. Seems an awkward line, but perhaps it is percentage as ♦Jxxx is a hefty 1/7 (i.e. 4 of the remaining 28 diamond lies) chance which is at least comparable to the risk of someone ruffing a spade when both minors are breaking.

It does seem that he was assuming an extremely high probability -- 90+%? -- that RHO would falsecard when appropriate.

[lamford]

ceeb, on Oct 11 2010, 10:55 AM, said:

nigel_k, on Oct 10 2010, 07:48 PM, said:

lamford, on Oct 11 2010, 01:17 PM, said:

I think it is very close, as Hamann's line also fails when clubs are 3-3 and East has Jxxx in diamonds. If they will always find the false count signal, I think he is right.

You might still succeed in this case but will need spades 3-3 or the ten dropping as you would have to use ♥A to shorten your trumps.

Alternatively Hamman might have been planning, if RHO followed to the 3rd club, to cash ♦K, and if all follow low unblock the ♠KJ immediately. Seems an awkward line, but perhaps it is percentage as ♦Jxxx is a hefty 1/7 (i.e. 4 of the remaining 28 diamond lies) chance which is at least comparable to the risk of someone ruffing a spade when both minors are breaking.

It does seem that he was assuming an extremely high probability -- 90+%? -- that RHO would falsecard when appropriate.

Maybe he thought that Zia was East rather than North! And Rodwell was no doubt miffed that declarer in the other room played for him not to have found it!

[aguahombre]

Yeh, I watched that hand at Hamman's table. The commentators, though generally rather snappish with each other, the Vugraph operator, and the specs ---pretty much put away their pomposity on that hand and let it slide (mostly).

Hamman made a choice, and he has a not so bad team, too. I am sure he just said "next".

[nigel_k]

Ceeb's line is better than mine. The probability of a falsecard from xxx that is needed to make a low ruff correct can be calculated as follows:

If you ruff with the ace you make about 50% of the time.

If you ruff low you make about 30% of the time when clubs are 4-2 and about 80% of the time when they are 3-3. The relevant 4-2 break (AKxx opposite xx) will occur about 9.6% of the time and the relevant 3-3 break is 7.2% multiplied by the likelihood they find the falsecard.

Solving for p in 0.5 = ( 0.3 * 9.6 + 0.8 * 7.2 * p ) / (9.6 + 7.2 * p) gives p = 0.89

If my maths is correct (and it may well not be) this is higher than I first thought and so you should probably always play the ace.

However it is more complex than that because of the double crossing element. For example, when East has the J of trumps and xx of clubs he might choose to show an odd number and hope partner continues clubs anyway. Therefore increasing the probability that he actually has xxx. Certainly that is the corollary of us deciding the Ace is always right.

But probably it's best to just play the ace and pay off to East when he has done something clever.

[benlessard]

Am I the only 1 to find it weird to not be at 3NT on that board ?

It take 4 cover cards for slam to be good

Kof C,A of S and 2 others A for 15 pts.

4A, wich is clearly a super accept of anything.