[helene_t]

Do non-natural responses to a natural (5cM presumably but that might not be essential) 1♠ opening belong here or in "Natural Systems"?

Anyway:
1NT NF (OK SF, I should stop flogging that dead horse)
2♣ GF relay
2♦ 5+ hearts, primarily less-than-gf hands
2♥ 3+ support, (8?)9+ support points
2♠ 3+(usually just 3) support, 4-7(8) support points
Higher responses I am not sure about, but maybe something like
2NT invitational with one long minor (could throw some extreme gf hands in also)
3♣ weak (6-9 ish) both minors
higher bids are various distributional raises, maybe also a couple of bids for hands with very long hearts

So for example
1♠-2♦
2♥-pass (six-card hearts, less than invitational)

1♠-1NT
2m-2♥ (five hearts as a consequence of the above)

Has anyone tried something like this?

[shyams]

I have not played such a structure. However, in the 2020 lockdowns, I had adapted a relay structure & shared with a friend. We never played with it but we discussed & debated for a bit.

My system used 2C as relay (artificial, not necessarily GF), 2D as 4+ hearts (not 5), 2H as 3+ spades, and 2S as INV relay in NT. My 1NT was 6-10 "to play" & need not be balanced.

Then, the approx outline
1. Over 1S-1NT, Opener can pass (the more frequent action) or bid naturally (2S is 6+ NF, 3S is 6+ card with extra strength) etc.
2. Over 1S-2D, Opener bids 2H if he began with 5S-4+H, bids 2S with 6+ or bids 2NT 'to play'.
3. Over 1S-2H, Opener obeys and bids 2S with most hands and lets Responder decide.
4. Over 1S-2S, Opener obeys and bids 2NT in most situations but breaks to new suit (3C, 3D, 3H) with 5-5 or 6-5 shapes.
5. Over 1S-2C, we tried to design a customised structure to show Opener's precise shape & strength. The idea was that the 2C bidder will take charge and bid on to the best level appropriate based on the info obtained.

It differs from yours in that Responder does not need 5-cards to relay, and Responder does not need two ways to show support.

I had proposed continuing the relay structure higher. So 1S-2NT is unbal with long clubs (may be weak), 1S-3C is unbal with long diamond etc. It remained an idea never fleshed out...

This post has been edited by shyams: Yesterday, 06:06

[DavidKok]

I think this structure gains on having the 2-level invite with 2♥, while losing a little on the 2♦ response and a lot on the 2♣ response. 1M-2♣ as a GFR is one of the worse relays in limited opening systems, starting so high and regularly making opener declarer, in addition to all the regular weaknesses relays have. Here you take on the additional burden that opener's hand is wide ranging, so responder is in a worse position to unilaterally place the contract.

If you want to keep this structure I'd consider making 2♦ GF (and showing 5(+) hearts). This unloads the 2♣ a little and reduces the frequency of finding opener's short suit too late. But either way I think this is worse than standard, sorry.

I've played 1♠-2♦ as an inv(+) heart transfer before, and I really struggled with the continuations. It is not safe for opener to make a low rebid with some extra values, but if responder is bidding on shape this can be awkward.

[mw64ahw]

Interesting to see something slightly different.
I've experimented with/play something similar and do use 1N as NF in a Standard American context
2♣ as a GF relay is often played and there should be enough space to resolve shapes, although I've yet to create structures that include GF with ♦/some ♥.
2♦ works well if played in a style similar to Ambra, but other mechanisms are often suitable for weaker ♥ based hands.
2♥ 3+ inv+ provides a couple of extra steps to differentiate between 3 & 4+-card support and strength. Again its may be useful to compare with Ambra
2♠ shows the support. I play constructive only
2N is OK if you're happy to lose 2N as 4+♠ GI/GF. I guess 3♦ accepts an invite in ♣
3♣ also works, but playing SA I tend to show this shape after 1N/interference and use 3♣ as natural inv. with inv. ♦ going through 2♣.

[awm]

Nystrom-Upmark play this and they are generally thought to be a decent pair. Their system notes only have a little bit on follow-ups on their card but it looks there is some more here and their relays are discussed here. Of course this could be a bit old but it's a reasonable starting point.

[awm]

I'll mention that Sam and I had enough trouble with 1♠-2♣ relay that we've been playing slightly different methods where 1nt is a one-round forcing response to 1♠ (either weak or relay). The extra step seems to matter quite a lot, plus we get to right-side notrump contracts.

[foobar]

Helene, assuming that you are playing a limited opening system, playing 1N as a GFR is better IMO.

1S:
....1N: GFR
....2C: Invite that can't immediately GF, but not 3♠
....2D: Hearts
....2H: Better ♠ raise, maybe 3-card LR that might take another bid
....2♠: Worse ♠ raise

This means that some hands without a fit and no other bid may have to pass 1♠, but this is seldom an issue playing limited openings.

More details available on request.