The positive responses 1♣-1♥♠ show 7+ points and 4+ cards. They are as natural
as in a natural bidding system. We also use conventions from 2/1, a ubiquitous
5-card major system.
Odwrotka 1♣-1M-2♦ is a fit reverse showing a game-forcing 3+ card support. The
jump reverse of the other major shows a game-forcing minor two suiter to
alleviate the burden on 2NT.
We use the relay structure in Polish Club 2020: Expert. The 2♥ response to
Odwrotka is a slam try with 11+ HCP or a certain fit and <= 8.0 NLTC. The
relay structure generally lets the strong opener declare notrump.
1♣-1M 2♦-
FG, 3+ SUPP
2♥!
(R) S/T, 11+
2♥ 2♠!
(R)
2♥ 2NT
Probably (4333)
2♠!
NEG, 7–10, 4=M
2♠ 2NT!
Ask for a side suit, a 5-card minor or the other 4-card major
2NT!
MIN, 7–10, 5=M, not BAL
2NT 3♣!
Ask for the side suit
3♣
Mild S/T, 9–11, 5+♣, 4=M
3♦
Mild S/T, 9–11, 5+♦, 4=M
3M!
MIN, 7–10, BAL 5=M
3OM!
SPL, 7–10, 0–1#, 6+M
3NT
MIN, 7–10, 6+M
4♣!
SPL, 7–10, 0–1♣, 6+M
4♦!
SPL, 7–10, 0–1♦, 6+M
Relay systems can be cryptic! I am summing up why we arrange the steps in this
way.
2♥: The lowest step layers strong hands. We can repeat the whole
structure inside. This step follows the logic of (reverse) Lebensohl.
2♠: The second step holds the possibility of a misfit, 4 cards. We
need space to explore games in the other strains.
2NT:Unbalanced fit! Opener never settles in 3NT. Feel free to bid
notrump.
3M:Balanced fit! Give opener a chance to declare 3NT with a flat hand.
3m: Take some hands out of the nebulous 2♠. These hands suggests a
minor suit slam.
Others: These Splinter-level steps are made for big fits.