[helene_t]

With one semi-regular p I play Dutch-style five-card-major, which is similar to SAYC except for some details that are not relevant for this topic.

We have the agreement that opener's non-reverse 2-over-1 rebid shows 15+ HCPs:
1♥/♠-1♠/NT
2♣/♦(or 2♥ after a 1♠-opening)

With a 5431-shape with 12-14 HCPs your options are to pass responder's 1NT, to rebid 1NT over 1♠ with a singleton in partner's suit, or support 1♠ on a 3-card.

I think it works very well. In practice, 1NT will rarely be the final contract (if we can't bid more, the opps will). If 1NT becomes the final contract, it may not be bad: the fact that the opps did not bid suggest that they don't have a long suit to run. Actually, bridge teachers often say that the main reason to introduce your second suit is to show that your first suit is a 5-card, but playing 5-card majors that is obsolete.

The advantage of this agreement is, of course, that the range of the rebids becomes more narrow. For example:
1♠-1NT
2♣-2♠
pass*
*with 16 points it is safe to pass since responder was allowed to make a positive second bid with 9 points.

With 5-5 or 5-4-4 you could bid a second suit even with a minimum, as long as respinder's first bid was 1NT - if he bids 2NT to show 9-10 HCPs you can still show your minimum by rebidding your second (or third) suit. After 1♥-1♠ things could get complicated (if responder forces to game) but that problem hasn't come up too often.

Is this a good idea?

[inquiry]

This is clearly playable. At times, the winner of part-score hands is often the first side to bid 1NT (especially on non-fit, roughly equally divided value). In fact, I love to play 1NT not vul. .

If you play 1NT and make you are +90, if you are down one, you are -50 but they might easily have made -90 if allowed to play. Likewise if you are down two (-100), they might have made 2NT (-120).

The math is a little altered if you are vul. Down one is 100 versus 90, down two is 200 verus 120. The way these numbers change suggest a valid reason why a vulnerable 1NT opening bid is often played "stronger" by pairs who play mini=NT (and not the fear of going minus a zillion doubled... it is this "gain" when you go down and they should be in NT that makes it less attractive, at least to me).

Ben

[MickyB]

I was considering the opposite of this just last night...how about a 1NT rebid showing 15+, can be fairly offshape? Makes slightly more sense playing weak NT obviously.

[pclayton]

I think its reasonable. I assume 1M - 1N - 2x is a one round force?

With the weaker 5-5's, I would suggest a direct jump to the 3 level to show this hand.

Sounds a little like Cole.

[pbleighton]

1) I think 1S/2H should be made on a minimum, otherwise you will miss games the field will reach. Otherwise, it is interesting, as long as the NT rebid is weak.
2) Does this apply over 1D/2C?
3) "I was considering the opposite of this just last night...how about a 1NT rebid showing 15+, can be fairly offshape? Makes slightly more sense playing weak NT obviously."
I play weak NT in the context of light Standard American, and the 1NT rebid shows 15-17 vul and 14-16 NV (we play 1NT as 12-14 vul and 10-13 NV). This is pretty standard treatment.

However, I think off-shape (not counting 5422) 1NT rebids are problematic with a higher rebid range, as there are more hands where responder has a 6 card major suit, and 2 card support puts him at or near game. Knowing the NT rebid guarantees 2 is important. OTOH, the weak rebid usually just gets passed out, or playing a 6-1 fit at the 2 level isn't so bad.

For a long time, my pd would make off-shape NT rebids to communicate hand strength. We weren't happy with the results, and now make them only when the alternative is worse.

Peter

[helene_t]

If 1M-1NT-1x is round force? No, it's 15-17. We've considered using 2♣ as a relay (some people use 1♠-1NT-3♣ as asking for the number of hearts). With 18-19 opener can rebid 2NT or 3x. However, 1♥-1♠-2x is forcing.

If it apples to 1♦-x-2♣? Yes.