Natural 1♦
- MIN (11–13): 4+♦, but 2+♦ by passed hand
- MAX (13–15): unbalanced 4+♦
| 1♦- | 11–15, 4+♦ |
|---|---|
| 1♥♠ | F, 4+# |
| 1NT | NF, 8–10 |
| 2♣ | INV+, 4+♣ |
| 2♦! | LIM+, 4+♦ |
| 2♥! | CONST P/C, 4–5♥, 5=♠ |
| 2♠! | INV, 5–6♠, 4=♥ |
| 2NT | BAL INV, 11–12 |
| 3♣! | CONST, 8–10, 5+♦ |
| 3♦! | PRE, 0–7, 5+♦ |
| 3♥♠! | SPL, 0–1#, 4+♦ |
By passed hand, 1♦ contains a weak notrump.
| P-1♦- | 11–15, 2+♦ |
|---|---|
| 2♠! | PRE, 6+♣. BAL INV. |
| 2NT! | PRE, 6+♦ |
| 3♣♦ | INV, 6+# |