lamford, on 2013-November-25, 08:54, said:
The authorised information, that partner pulled 3NT to 4S, but did not open a weak two spades, makes 5D automatic for me. If partner does have two aces, then 5D will be fine.
RMB1, on 2013-November-25, 10:25, said:
If 4♠ doesn't exist then I think it is clear that Pass is a logical alternative.
wank, on 2013-November-25, 10:26, said:
it's easy to use this kind of soft logic to justify using UI (i'm guessing 3nt was alerted as some sort of raise), but it's all a fallacy. there are plenty of other reasons why partner might choose not to open a pre-empt with a long spade suit - a heart suit on the side, or a plan to be sneaky later in the auction, for example.
FrancesHinden, on 2013-November-26, 14:58, said:
What RMB and wank said. Partner pulls our 3NT bid to game in spades. Pass is always a logical alternative. More so if the bid systemically doesn't exist, not less so.
dburn, on 2013-November-27, 09:48, said:
Pass is automatic. 5♦ is illegal.
lamford, on 2013-December-01, 16:38, said:
But 16B1(b) defines an LA as "<snip> using the methods of the partnership", so, even if system violation is possible, LAs are decided assuming that the methods of the partnership are being used.
Lamford notes that for CyberYeti, pass isn't an LA, because, according to his partnership methods, partner has fewer than 6
♠. Other opinions seem right in common sense but wrong in Bridge-Law.