[awm]

Here's a suggestion:

2NT = limit raise or better
1♠-3♥ and 1♥-3♦ = mixed raise
1M-3M = weak

1♠ - 3m = natural invite
1♥ - 3♣ = natural invite

When holding long hearts over partner's 1♠, start with 1NT. The plan is to rebid 2♥ with a weak hand and 3♥ with an invitational hand. If partner somehow rebids 2♥ of course you raise to game. If partner rebids 2♠, you pass with the weak hand with hearts and bid 3♥ with the invitational hand.

When holding long diamonds over partner's 1♥, start with 1NT. The plan is as follows:

1♥-1NT-2♣: Bid 2♦ with weak and diamonds, 3♦ with inv and diamonds. 2♠ is a strong club raise.
1♥-1NT-2♦: Bid 3♦ with weak and diamonds, 2♠ with inv and diamonds. 2♠ is a strong diamond raise.
1♥-1NT-2♥: Bid 3♦ with weak and diamonds, 2♠ with inv and diamonds. 2♠ is invitational with either 6+♦ or 5/5 minors.

[hirowla]

Thanks everybody for your suggestions. How does this sound for a possible structure:

After a 1♠ opening:

2♠ 6-9 with 3 card support
1NT followed by 3♠ 10-12 with 3 card support
3♠ 6-9 with 4+ card support (sometimes with 5+ support jump straight to 4)
2NT limit plus with 4+ card support. Play as a modified Jacobs 2NT
3NT 10-12 HCP plus unspecified singleton/void (splinter)
3♣/3♦/3♥ 10-12 with 6+ in the bid suit
No bid for 0-6 pts and 4+ trumps (not really useful)

Over a 1♥ opening:

2♠/3♣/3♦ 10-12 with 6+ in the bid suit
3♠ 10-12 HCP plus unspecified singleton/void (splinter)
Rest of the bids similar to above

The reason I'm keen on the jump invite bids is some experiences where those bids could previously only be shown with 1NT then a bid. In the meantime opener jumped the bidding and hence the hand couldn't be shown. That caused issues. With this, going via 1NT then bidding a suit is now only weak.

Note: this structure doesn't include competitive bidding, but that's another story! Also that Kaplan Inversion is played so the impossible 2S bid can't be used as such (it is used though).

Thoughts?

Thanks,

Ian