Natural 1♦
This opening shows 5+♦ or unbalanced 4=♦ 1–5♣. Unlike Polish Club 2020, I use standard (i.e. non-inverted) minor raises along with mixed raises to maximize preemption. This method utilizes the frequent 5th diamond in the 1♦ opening.
Note that 1♦-2♣ is sometimes a phony suit. It is the only way to bid a game-forcing hand with long diamonds and no side major suit.
| 1♦- | 11–20, 4+♦ |
|---|---|
| 1♥ | F, 4+♥, usually 6+ |
| 1♠ | F, 4+♠, usually 6+ |
| 1NT | NF, 6–10, 4+♣ |
| 2♣ | FG, 4+♣ or 4+♦ |
| 2♦ | CONST, 5–9, 4+♦ |
| 2♥! | P/C, 5–9, 4–5♥, 5=♠ |
| 2♠! | INV, 9–11, 5–6♠, 4=♥ |
| 2NT | BAL INV, 10–11 |
| 3♣! | INV, 9–11, 6+♣ |
| 3♦ | INV, 9–11, 4+♦ |
| 3M! | PRE, 3–6, 7+# |
| 3NT | 11–15, 1–3♠, 1–3♥ |
P-1♦
Game forcing 2♣ becomes a natural invitation. Consequently, 2♠ is a limit raise because it no longer takes care of clubs. Preempts also become invitations due to failure to open.
| P-1♦- | 11–20, 4+♦ |
|---|---|
| 2♣ | INV, 5+♣, 0–3♠, 0–3♥ |
| 2♠! | LIM, 3+♦ |
| 3M | INV, 9–11, 6+# |