Positive 1NT, 2♠, and 2NT
I group these suitless positive responses together for simplicity. These responses deny 4-card majors and 6-card minors. I also list 1♣-3NT here as reference because it takes precedence over 1♣-2NT.
| 1♣- | Strength | Distribution |
|---|---|---|
| 1NT | 8–10 | 2–3♠, 2–3♥, 2–5♦, 2–5♣ |
| 2♠! | 10–11 | 0–3♠, 0–3♥, 2–5♦, 2–5♣ |
| 2NT | 12+ | 2–3♠, 2–3♥, 3–4♦, 3–4♣ |
| 3NT | 12–15 | 33(43) |
1♣-1NT
I make 2♣ and 2NT weaker than in Polish Club 2020: Expert to be more descriptive and passable.
| 1♣-1NT- | BAL 8–10 |
|---|---|
| 2♣ | S/O, 12–14, 6+♣ |
| 2♦ | S/T, 18+, 4+♦ |
| 2M | S/T, 18+, 5+# |
| 2NT | INV, 14–15 |
| 3♣ | S/T, 18+, 5+♣ |
| 3♦ | S/T, 18+, 6+♦ |
| 3M | S/T, 18+, 7+# |
| 3NT | S/O, 16+ |
| 4♣♦ | S/T, SOL 7+# |
1♣-2♠!
I move unbalanced invitations here from 1♣-1♦. Opener declares notrump anyway, so 1♣-2♠ need not be balanced.
| 1♣-2♠- | INV 10–11 |
|---|---|
| 2NT | S/O, 12–13 |
| 3♣ | S/O, 12–13, 6+♣ |
| 3♦! | S/T, 18+, 0–4♠, 0–4♥ |
| 3M | S/T, 18+, 5+# |
| 3NT | S/O |
| 4♣♦♥♠ | S/T, SOL 7+# |
P-1♣-2♠ only contains unbalanced hands of both minors. Hence, 3♦ becomes a reasonable signoff.
| P-1♣-2♠- | INV, 4–5♦, 4–5♣ |
|---|---|
| 3♦ | S/O, 12–13, 4+♦ |
1♣-2NT
Moving balanced game force from 3NT to 2NT was a brilliant idea from Polish Club 2005. It is difficult to search for a major suit slam after 1♣-3NT. Therefore, 1♣-3NT is restricted to a flat minimum game force.
I make 1♣-2NT-3NT highly descriptive here to help slam exploration. This method makes 3♣♦ inclusive like relays.
| 1♣-2NT- | BAL FG |
|---|---|
| 3♣ | 5+♣ |
| 3♦! | 0–4♣ |
| 3M | S/T, 5+# |
| 3NT | S/T, 15–17, 4414 |
| 4♣♦♥♠ | S/T, SOL 7+# |
P-1♣-2NT degenerates to a balanced invitation, which is in turn similar to unpassed 1♣-2♠. I import continuations from 1♣-2♠ as a natural consequence.
| P-1♣-2NT- | BAL INV |
|---|---|
| 3♣ | S/O, 12–13, 6+♣ |
| 3♦! | S/T, 18+, 0–4♠, 0–4♥ |
| 3M | S/T, 18+, 5+# |
| 3NT | S/O |
| 4♣♦♥♠ | S/T, SOL 7+# |