pran, on Nov 25 2009, 06:03 AM, said:
With multi the uncontested auction 2♦ - 2♥ - 2NT - 3♣ is typically identical to the auction 2NT - 3♣ when 2NT shows 20-21 balanced.
However, while 3NT is a relevant bid after 3♣ in the second case it is definitely not so in the first case (when using multi).
Therefore I would (as director) accept 2NT - 3♣ - 3NT to be evidence from the auction alone (i.e.authorized information) that opener had forgotten the agreement to use multi and having a 20-21 strong balanced hand.
Sorry, I don't get why 3NT is a possible response to a 3
♣ enquiry after a natural 2NT opener, but not after the strong balanced version of a Multi.
Except for the players who distinguish distribution by the two sequences (2N shows 20-22 without a 5-card suit, after which 3
♣ is Baron; a 2N rebid after a Multi shows the same range with a 5-card suit, after which 3
♣ merely asks for the suit: surprisingly common around here) nearly everybody who uses different sequences to 2NT to show different ranges of strong balanced hand uses the same response structure thereafter (at least if responder has shown nothing in particular with a negative or relay response to a 2
♣, 2
♦ - or in my case a strong 1
♣ - opening).
I am therefore with bluejak: if you have a comparable sequence ending in 2NT, to which a 3NT response has an agreed meaning, then you assume that partner has some range of strong balanced with the same hand-type as is shown by 3NT in the comparable sequence.
If a 3NT response in the comparable sequence has no agreed meaning, then partner is guilty of unauthorised panic, and bluejak is quite right to be cross with him.
In principle, absent UI, you are free to guess a level, as I doubt partner's forget demonstrably suggests any particular range over any other, but if partner's response to Stayman (or whatever you play in comparable sequences) would have got you into trouble, and you fall on your feet after his 3NT rebid, then your side is going to get adjusted against because of partner's actions, not yours, so it matters little what you do. I might well pass as the option best calculated to get partner not to do it (either the initial forget or the UP) again.