easy one

[Finch]

This is really a stupid question.  Anyone who provides arguments as to what he would respond based on an analysis of the pros and cons of the situation and the strengths and weaknesses of the hand is bidding like a friggin' moron.  You either have agreed to constructive raises or you have not.  If you have, you must bid 1NT.  If you have not, you must bid 2♠.

I don't agree.

 

I agree that system is relevant, but there is still a decision. I don't know what basic SAYC actually says about raising partner.

 

If you have agreed constructive 2-level raises, pre-emptive 3-level raises and that a bad 3-card raise bids 1NT you have the choice of pass, 3S or 1NT

 

If you have not agreed constructive or pre-emptive raises you have the choice of 2S, pass or a potentially (semi-)psychic 1NT

 

There's no 'must' about any of this. In traditional bidding, as taught to beginners, the technically correct call is to pass as you don't have enough to respond.

[kenrexford]

I find it hard to believe that passing with four-card support, a doubleton, and one control is ever right. But, if you are conservative, then the dispute should be between 1NT (because you have that tool available) and pass (because you do not). Assessing values for 1NT, 2M, and P is silliness. Assessing values between 2M and P, for those who do not use constructive raises, is the only logical analysis possible.