Checkback (pro) occurs in sequence: 1m–1M-1NT–2♣ and guarantees five and 11+ HCP or four and 14+ HCP.
- 2♢ -no support 12- HCP;
- 2 in partner's suit - support 12- HCP,;
- 2 in the second major - support 13-14 HCP;
- 2BA - 13-14 HCP no support.
After the intervention of the opponents, the balance bid.