Natural 1♥-1♠
As the opening is limited to 12–17, the reverses are not forcing. The reverses show a maximum 5+ 5+ two suiter.
| 1♥-1♠ | 4+♠ |
|---|---|
| 1NT | BAL 12–14 |
| 2♣ | 11–17, 4+♣; BAL 15–17 |
| 2♦ | 11–17, 4+♦ |
| 2♥ | 11–14, 6+♥ |
| 2♠ | 11–14, 4+♠ |
| 2NT! | 15–17, non-SOL 6=♥ |
| 3♣♦ | 15–17, 5+# |
| 3♥ | 15–17, 6+♥, S-SOL or 7+♥ |
| 3♠ | 15–17, 4+♠ |
| 3NT! | Gambling, 7+♥ AKQ, no outside A/K |
| 4♣♦! | SPL, 0–1#, 4+♠ |
BTU 3-way checkback
BTU checkback is also in effect after 1♥-1♠-1NT, similar to 1♦-1M-1NT. 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♠ 1NT- | BAL MIN |
|---|---|
| 2♣! | BTU CB, F1 |
| 2♣-2♦ | P/C |
| 2♣-2♥! | P/C, 4+♦ |
| 2♣-2♠! | MAX, 3=♠ |
| 2♦! | FG CB |
| 2♥ | INV, 2–3♥ |
| 2♠ | INV, 5+♠ |
| 2NT! | TRF, PRE or FG, 6+♣ |
| 3♣ | S/T, 5+♣, 5+♠ |
| 3♦ | S/T, 5+♦, 5+♠ |
| 3♥ | S/T, 3+♥ |
| 3♠ | S/T, 6+♠ |
| 1♥-1♠ 1NT-2♣ 2♦- | P/C |
|---|---|
| 2♥ | S/O, 2+♥ |
| 2♠ | S/O, 5+♠ |
| 2NT | BAL INV |
| 3♣ | INV, 6+♣ |
| 3♦ | INV, 6+♦ |
| 3♥ | MAX INV, 53(32) |
| 3♠ | MAX INV, 6+♠ |