"(1S)-1NT show 15-17, 15-18, or 16-18 depending upon your style. You need the good values, because your partner's hand is unknown. However,
(1S)-P-(P)-1NT is typically 11-13, 10-14, 12-14, something like that (you have to agree with your partner what your balancing NT range will be). But here, you know your partner has some hcp, so you bid NT with less. This allows you to bid with hands where DBL or overcall don't make sense."
I have always played them the other way round! It still seems more logical, ;D.
In the first case (1S)-1NT says I have a 1NT opener (12-14), with a Spade guard. As it does in the sequence (p)-p-(1S)-1NT, partner knows the limit of competition and can assess their hand appropriately.
It happened yesterday, I held AT5-K84-AT9-J982, a perfect Weak NT, we played in a Heart partial. If I don't play a Weak NT, I have no bid... Say opener's partner raises to 2S & partner balances? What is my bid?
In the second case, am I really going to announce that I have balanced rubbish sat under an, almost, unlimited opener? Need a finesse? Guess what! Nah!
With a Weak NT in balancing position, double is just fine,
![:)](http://www.bridgebase.com/forums/public/style_emoticons/default/biggrin.gif)
But, partner plays them the "wrong" way round... I guess I have to adapt, lol.
P.S. Ben played that one too, & defeated 2SX... WD Ben.