Positive 1M

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.

1♣-1♥-7+, 4+♥
1♠F, 4+♠
1NTBAL 12–14, 2–3♠, 2–3♥
2♣UNBAL, 12–17, 5+♣, 0–3♠, 0–3♥
2♦!FG, 3+♥
2♥MIN, 12–14, 4=♥
2♠!FG, 5+♦, 5+♣
2NTFG, 2–3♠, 1–2♥, 3–5♦, 3–5♣
3♣FG, 6+♣
3♦FG, 6+♦
3♥INV, 15–17, 4+♥
3♠!SPL, 0–1♠, 4+♥
3NTSOL 7+♣, partial stops in ♠ and ♦
4♣!SPL, 0–1♣, 4+♥
4♦!SPL, 0–1♦, 4+♥
1♣-1♠-7+, 4+♠
1NTBAL 12–14, 2–3♠, 2–3♥
2♣UNBAL, 12–17, 5+♣, 0–3♠, 0–3♥
2♦!FG, 3+♠
2♥FG, 5+♥
2♠!MIN, 12–14, 4=♠
2NTFG, 0–2♠, 2–4♥, 2–5♦, 2–5♣
3♣FG, 6+♣
3♦FG, 6+♦
3♥!FG, 5+♦, 5+♣
3♠INV, 15–17, 4+♠
3NTSOL 7+♣, partial stops in ♥ and ♦
4♣!SPL, 0–1♣, 4+♠
4♦!SPL, 0–1♦, 4+♠
4♥!SPL, 0–1♥, 4+♠

BTU 3-way checkback

We use BTU-style 3-way checkback to an XYZ auction. There are 3 artificial relays in the 3-way checkback:

  • 2♣: several variants:
    • to play 2X
    • strongly shaped invitation
    • balanced invitation or choice of games
  • 2♦: game-forcing checkback, usually a choice of games
  • 2NT: transfer to clubs

As a corollary, natural 2X are wide-range invitations and 3X become slam tries.

1♣-1♥-1♠

In this particular case of BTU checkback, opener can pass 1♣-1♥; 1♠-2♣ with minimum long clubs. Otherwise, BTU checkback is forcing.

1♣-1♥-1♠-F, 4+♠
1NTMIN, 7–10, 0–3♠, 4–5♥
2♣!BTU CB, NF
2♦!FG CB
2♥INV, 5+♥
2♠INV, 4+♠
2NTTRF, PRE or FG, 6+♣
3♣S/T, 5+♣, 5+♥
3♦S/T, 5+♦, 5+♥
3♥S/T, 6+♥
3♠S/T, 4+♠
3NT12–15, 0–3♠, 4=♥, 0–5♦, 0–5♣
1♣-1♥; 1♠-1NT-NAT MIN
2♣NF, 12–15, 5+♣
2♦!4SF1, INV+, 0–2♥
2♥INV, 3=♥
2♠FG, 5+♠
2NTINV, 16–17, 0–2♥
3♣FG, 6+♣
3♦FG, 6+♦
3♥FG, 5+♠, 3=♥
1♣-1♥; 1♠-2♣-BTU CB
PS/O, 12–13, 6+♣
2♦!MIN, 12–15
2♥INV, 3=♥
2♠FG, 5+♠, 0–2♥
2NTFG, 4=♠
3♣INV, 16–17, 5+♣, 0–2♥
3♦FG, 5+♦
3♥FG, 5+♠, 3=♥
3♠!FG, 5+♣, 4=♠, 0–2♥
3NTMild S/T, 21–23, 4=♠
1♣-1♥; 1♠-2♣; 2♦-MIN, 12–15
PMIN, 5+♦
2♥UNBAL MIN, 5+♥
2♠MIN, 4+♠
2NTBAL INV
3♣INV, 6+♣
3♦INV, 6+♦
3♥INV, S-SOL 6+♥
3♠INV, 4+♠, 5+♥

1♣-1♥-1NT

1♣-1♥-1NT-BAL 12–14
2♣!BTU CB, F1
2♣-2♦!P/C
2♣-2♥MAX, 3=♥
2♦!FG CB
2♥INV, 5+♥
2♠INV, 4+♠
2NTTRF, PRE or FG, 6+♣
3♣S/T, 5+♣, 5+♥
3♦S/T, 5+♦, 5+♥
3♥S/T, 6+♥
3♠!SPL, 0–1♠, 6+♥
3N12–15, 4=♥
4♣!SPL, 0–1♣, 6+♥
4♦!SPL, 0–1♦, 6+♥
1♣-1♥; 1NT-2♣; 2♦-BAL 12–14, P/C
2♥S/O, 5+♥
2♠INV, 4+♠, 6+♥
2NTBAL INV
3♣INV, 6+♣
3♦INV, 6+♦
3♥INV, S-SOL 6+♥
3NTChoice of games, 5♥(332)

1♣-1♠-1NT

1♣-1♠-1NT-BAL 12–14
2♣!BTU CB, F1
2♣-2♦!P/C
2♣-2♥MAX, 4=♥
2♣-2♠MAX, 3=♠
2♦!FG CB
2♥INV, 4+♥, 5+♠
2♠INV, 5+♠
2NTTRF, PRE or FG, 6+♣
3♣S/T, 5+♣, 5+♠
3♦S/T, 5+♦, 5+♠
3♥S/T, 5+♥, 5+♠
3♠S/T, 6+♠
3NT12–15, 4=♠
4♣!SPL, 0–1♣, 6+♠
4♦!SPL, 0–1♦, 6+♠
4♥!SPL, 0–1♥, 6+♠
1♣-1♠; 1NT-2♣; 2♦-BAL 12–14, P/C
2♥INV, 5+♥, 5+♠
2♠S/O, 5+♠
2NTBAL INV
3♣INV, 6+♣
3♦INV, 6+♦
3♥INV, 4+♥, 6+♠
3♠INV, S-SOL 6+♠
3NTChoice of games, 5♠(332)

Odwrotka with the strong 2♥ relay

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+M
2♥!S/T (R), 11+
2♥-2♠!(R)
2♥-2NTProbably (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
3NTMIN, 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.
1♣-1M; 2♦-2♥; 2♠-(R)
2NT4=M
2NT-3♣!Ask for a side suit
3♣4+♣, 5=M
3♦4+♦, 5=M
3oM4+#, 5=M
3M!BAL 5=M
3NT!6+M
4♣!SPL, 0–1♣, 6+M
4♦!SPL, 0–1♦, 6+M
1♣-1M; 2♦-2♥; 2♠-2NT; 3♣-Ask for a side suit
3X4+#
3M!4+♣
3NT4M(333)