Failure to Alert - Adjust to...?
Board 3 - Dealer S, E/W Vul The Bidding
S Q 4
H J 10 5 4 N E S W
D K Q 10 7 3
C 6 2 1NT 1 2S
S A K 9 8 7 2 S J 6 5 2NT 2 3S 3NT Pass
H 3 2 H Q 8 6 4D Pass Pass Pass
D 4 D 9 6 5
C K J 10 8 C A 7 5 4
S 10 3 1 Announced as 12-14
H A K 9 7 2 Lebensohl, but NOT alerted
D A J 8 2
C Q 9 3
After 3 passes, W asked (before E had selected a lead) S what 2NT showed. S stated 11-12 pts and S stop. N immediately corrected this and stated it was Lebensohl requiring S to bid 3C if E had passed. If weak, N would pass or correct to 3D or 3H to show a hand with no game ambitions, and there were stronger options, which were not relevant in this auction. E reserved their rights and the TD was called who instructed the hand be played and she be called back at the end of play. (Convention card confirmed Lebensohl, and S confessed his error)
At the end of play 4D was -1, and the TD requested to see the traveller which showed +100 x1, -50 x2, -140 x2, -170 x2, -200 x1.
S failure to alert was accepted as innocent and had he realised would have passed E 3S yielding -170 or -140.
W or E could have bid 4S in any event, yielding -620 or +100.
Have E/W been damaged? If so, should the TD have allowed the auction to be rewound three bids?
Finally, if an adjusted score is to be awarded, what should it be?
Comments
The TD should give West the opportunity to change their final Pass once the misinformation has come to light.
North has unauthorised information from the failure to alert, is passing 3NT a logical alternative? From North's perspective, South did not have to bid 3NT, so it must be a suggestion to play. The TD would have to poll. If Pass is a logical alternative to 4D, the adjustment would be 3NT -6 (or so).
If West knew that 2NT was Lebensohl, they might double 3NT and perhaps EW would bid 4S over 4D. We can only rewind the last Pass by the non-offending side at the table; and we cannot rewind the 3NT bid (unless East would not bid 3S) in assessing an adjusted score, because that is what South bid. We could allow EW to play 4S some of the time, sympathetically weighting the number of tricks. For example: 50% table result -50, 20% 4S-1 +100, 30% 4S= -620.
I'm also wondering why South passed 4D, since in his later explanation he was still offering 11-12 points with a spade stop as the explanation for 2NT. It should be considered whether, after the 4D bid, he'd "woken up" that 2NT had been Leb and didn't feel inclined to let anyone know. From his perspective, believing the 2NT bid to be natural, 4D is a bizarre bid.
North has unauthorised information from the failure to alert, is passing 3NT a logical alternative? From North's perspective, South did not have to bid 3NT, so it must be a suggestion to play. The TD would have to poll. If Pass is a logical alternative to 4D, the adjustment would be 3NT -6 (or so).
Surely N can see that if S has a 12-14pt hand of balanced distribution, 3NT cannot be a sensible contract with both oppos bidding Vul. Even if S had 2 Spade stops and AD he could not have the other suits covered.
As N, I took the 3NT bid as encouraging me to save over oppos 3S at the favourable Vulnerability. I assumed that S had recognised Lebensohl, but merely failed to alert. His belief that it was 11-12 pts opposite his 14, with both oppos bidding vulnerable seems incredible. I would not have expected 4S to have any chance on less than half the points with what appeared from the bidding to be relatively balanced hands, thus 4C/D/or H -1 looked a good save over 3S.
The first thing to note: E/W haven't been damaged by S's misbid, because you never correct for misbids, only misinformation (and things like UI). So in any projected auction, S's 3NT stands (unless E bids differently over 2NT).
I'd expect E's immediate 3!s to be the choice of many players even knowing that 2NT is Lebensohl; Lebensohl has strong options, after all, and E is probably expecting one, so 3!s has both pre-emptive and competitive value. So the only bids we have to look at from an MI point of view are E/W's final three passes (N's 4!d is also worth looking at, as it may have been affected by UI).
I'm inclined to agree with funatical's determination that there's no hand that would open a natural 1NT and then subsequently bid a natural 3NT after a pre-empted Lebensohl; South can't know that North doesn't have a weak hand (in fact, North does have a weak hand!). The logical meaning of 3NT to me is as pass-or-correct: "if you have a strong hand, I want to play here, otherwise correct to your suit". In any case, it seems obvious to pull as North opposite any hand that can possibly open a weak 1NT, so I don't think North's been affected by UI here.
As for the MI, Note that North (who knew 2NT was Lebensohl) should have alerted South's 3NT bid (because assuming the partnership agreements are followed, regardless of its meaning, it surely can't be natural opposite a two-way bid like North's); that would have helped in this situation, because E/W would have understood the situation at the time they made the MI-affected bids (their three passes). Then we wouldn't have to guess what would have happened; we'd know. As it is, we can rewind one pass (undoing West's final pass), but can't rewind further in the auction than that.
We do, however, have to try to project an auction (or weighted combination of auctions) to work out what to adjust to, assuming that E/W have been told that 2NT is Lebensohl, and 3NT is "no agreement, but obviously not to play if N has a weak hand". This will depend somewhat on E/W's partnership agreements; assuming that X of 3NT is penalty, I can see a reasonable chance that West will do that, in which case East (who hasn't shown any strength so far in the bidding) might well try 4!s over 4!d.
All that said, I find it hard to see damage here, on the basis that E/W are unlikely to have had accessible spots better than -50. If North's 4!d is ruled to have had no logical alternatives (and I'd rule that), the only contracts we can possibly end up in are 4!c by E/W (which AFAICT can actually be made, but I don't see them finding it; if E/W can show that their system can reach it over this start, though, I'd be sympathetic); 4!d by North (table result); and 4!s by West (which looks like it's going down, unless S carelessly cashes hearts before N leads them, which seems unlikely given that S can see the Queen in dummy; you might want to give some weight to this possibility, but the table result is likely worth more matchpoints than the average matchpoint score for the weighted results). If players were available to poll, it might be worth polling them to determine a) the chance of E/W reaching each possible contract without the MI and b) the chance of 4!s making.
If my partners bid an unexpected 3NT, I give serious consideration to passing.
Perhaps he has discovered an ace, or that some of his spades are clubs.
I certainly have more points overall and fewer cards in my long suit than I might have.
Well, in this situation, your partner doesn't know what you have. It's perfectly plausible for your partner to bid 3NT as "if you were thinking of 3NT, let's play it", but that doesn't mandate pulling it if 3NT was the last thing on your mind. Your partner cannot reasonably jump to 3NT regardless of whether you have a weak or a strong hand, though; if their hand is such that they want to be in game opposite a weak hand, they probably want to slam explore opposite a strong hand. (If North actually had the strong-and-balanced option for Lebensohl, would we be UI-adjusting if North passed 3NT in this sequence? If not, we probably shouldn't be UI-adjusting for a bid over 3NT when holding the weak option.)