High Level Decision

[sailoranch]

If she was about to pass 5♠X and a swinging opponent who is down in the match redoubles, how can pass no longer be an LA?

 

This is probably my misunderstanding of the laws, but I thought an LA was determined by what South's peers would have done in the actual auction without the UI, not what South would have done in a different auction with the UI. The polled players have to bid according to South's partnership understandings, but do they have to use her judgment?

[jogs]

I think the fact that you are leading in the match makes passing clearer, much for the reasons lalldonn gives. Partner is unlikely to double 5S without the nuts, especially as you have had a good 7 boards to add to your 20 lead. Except that you know that partner does not have the nuts from the dithering.

 

Your singleton diamond and KQ clubs is much better for defence than something like x KQJxxx Jx QJTx. In my view, not only is there no LA to Pass, it is the best bid, although I would indeed have bid 6H last round. With UI it is not close.

 

By your own admission she can only lose the match if 5♠XX makes. That means 6♥X is a losing action if and only if it goes down four or more. Pulling is clearly the correct game theory action. Partner's BIT has no effect on this decision. In fact partner should have passed 5♠. Partner by passing 5♠ wins the match.

[lamford]

By your own admission she can only lose the match if 5♠XX makes. That means 6♥X is a losing action if and only if it goes down four or more. Pulling is clearly the correct game theory action. Partner's BIT has no effect on this decision. In fact partner should have passed 5♠. Partner by passing 5♠ wins the match.

If boards were scored up one at a time, and the result in the other room on this board was known, you would be right. In reality, all our opponents knew was that they led by 20 with 8 to play, and that the 7 as yet unscored boards in this segment were unlikely to be out. In practice they actually led by only 5 with this board to come, and the result in the other room was 5S doubled making. It is difficult to apply game theory to such incomplete information, and the only common sense approach is to try to avoid a big swing out when leading, and try to avoid swings if possible. But for ruling, all we need to decide is whether Pass is an LA, and, as jallerton points out, what percentage of the time the original doubler would pull it. If we disallow 6H we include 0% of that bid now, but can include 6H reached by another route.

[sailoranch]

What would have happened if South passed and West went down in 5♠XX? Can East-West make the case that the UI suggested North was thinking about bidding on instead of doubling?

[lamford]

What would have happened if South passed and West went down in 5♠XX? Can East-West make the case that the UI suggested North was thinking about bidding on instead of doubling?

If passing was demonstrably suggested by the BIT, and was an LA not selected by a significant number of South's peers, then in theory yes. There was a ruling in Pula where someone had an obvious 4S bid, but passed because his partner thought over 4H. The AC decided that the BIT had been designed to silence him, and adjusted the score. And regarding your other question, the LAs are determined by selecting peers with the same methods and style. Quite hard to do, and "similar" is used instead of "same" in practice.

[jogs]

Pulling is 'demanded' by your redouble. But the double of 5♠ is a terrible game theory call. And I don't even know partner's hand.