I very much doubt that 2N showed a 'weak' hand, even if the opps explained it as such.
I would be willing to bet that it shows a hand that prefers to play 3m rather than 1N, which is not the same thing at all.
x xxx AJx KJxxxx
That is a 2N bid, intending to pass 3C. I would hardly call it 'weak': our side has the majority of hcp, but 3N is a long way off and I surely don't want to let the opps compete in a major, at the 2 level.
This comment has nothing to do with what I would choose with the OP hand, since responder would bid the same way with x xxx xxx Jxxxxx
I have played a lot of weak 1N methods, in several partnerships, and the ability to jam the auction with a wide range of responding hands is one of the upsides to the method.
Imagine responder with 3=3=6=1 9 count and we compete. We could bemgoing for 500 or more against a partscore.
Imagine responder with a 1=3=6=3 3 count: we've just missed a vulnerable game if we pass
As for earlier action, while it is so easy to say that double of 2N is a major suit takeout, my suspicion is that the same players who make that argument would, were the hand KQx AJxx AJx Kxx, say that clearly the double shows a strong notrump type of hand
Now, will partner do if we double?
He may well be 3=3=3=4 or (32) 4=4 or some 3325 with 5 clubs. If he has 4 diamonds and values, he'll defend. Obviously we are laughing if he has a 4 card major: he can bid 3M or 4M. What if he bids 4C? Ugh, since that may well fetch a double from responder.
So part of me, the part with the chicken DNA, says stay stuck. The other part of me says that it is dangerous to bid but more dangerous to pass. So I double and take my chances.
Btw, I reject 4D. Yes, it shows both majors, but why on earth do we think that partner has an opening hand? And it he does, is he incapable of looking at it after we double 3D?
The notion that opps will look for 3N holding a 7 or 8 count with a 6 card minor makes me laugh. I'd love to play against those pairs at any form of scoring.
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari
ahydra asks 'IMPs, vul vs not. Would you bid here (or on the previous round)?'
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IMO you should double 3♦ -- and doubling 2N would have been even safer.