[jmc]

Partner and I are considering playing 2NT forcing after our 11-15 1D Opener. Our 1NT opener is 14-16. Were figuring 3NT is 17-19 and 2NT 13-16 or 20-21. All the NT responses deny a 5-card major.

What are the best responses over a forcing 2NT?

We were playing 3C both minors min, 3M both minors with major shortness max, 4C highly invitational both minors, 4D highly invitational single suiter, and 4M as 6D and a 5-card major. Any one have a structure they'd like to share? It seems like we should be able to better than this. Perhaps some relays could be used to untangle various distributional shapes.

[jmc]

How about this?

1D-2NT

3C single suited diamond hand
3D asks
3H club shortness
3S heart shortness
3NT spade shortness
3D (54)(31)
3H Asks
3S 31(54)
3NT 13(54)
3H 1255
3S 2155
3NT to play
4m perhaps pure minor hands with nothing in the majors
4M 56 major minor 2-suiter

[awm]

I think it's important to show major suit shortness on (41)53 type hands since that's the suit most likely to be weak in responder's hand. Perhaps something like:

3♣ = both minors; now 3♦ asks shortness
3♦ = long diamonds, responder just cuebids or bids 3NT with an unsuitable hand for slam
3M = either 4M with 0-1OM (i.e. 4153 types) or 5-6 hand (the latter bids on over 3NT from partner)
3NT = natural

[awm]

Looking at this further, it seems like the most important thing to show is normally shortness. If opener has no shortness, you will usually want to play in 3NT (especially assuming responder does not bid 2NT with two small in a side suit). I guess one question here is whether you're bidding 2NT with a four-card major; it seems that you are at least sometimes so it may also be worthwhile to have a way to find major suit fits. Maybe something like this:

3♣ = short in a major, not necessarily a club suit (4153 for example is allowed)
3♦ = short in clubs
3M = natural; usually four in the bid major without shortness, but can also be a 5-6 hand
3NT = (semi?) balanced with no four-card major

1♦-2NT-3M
... 3♠ = four spades, not four hearts
... 3NT = no major fit
... 4x = cue agreeing major

1♦-2NT-3M-3NT
... non-pass = 5/6 hand

1♦-2NT-3♦
... 3M = four card suit (basically bidding four-card suits up the line, 3NT by opener conditional on club stopper)
... 3NT = to play, good club holding for 3NT
... 4♣ = strong slam try in diamonds (good club holding opposite shortness)

1♦-2NT-3♣
... 3♦ = asking
... 3M = four cards in bid major, good 3NT holding in the other major (choice of game)
... 3NT = just want to play here regardless

1♦-2NT-3♣-3♦
... 3♥ = short spades (now 3♠ shows 4 hearts, 3NT to play, 4m suggests a strain)
... 3♠ = four spades, short hearts (now 3NT to play, 4m suggests a strain, 4♥=strong 4♠ bid, 4♠=to play)
... 3NT = less than four spades, short hearts (now 4m suggests a strain, pass to play)

1♦-2NT-3♣-3♦-3♥-3♠
... 3NT = less than four hearts
... else = cue agreeing hearts