Used after the partner opening 1♡/1♠ and no intervention with 13+ HPC and a 3-card fit.
- three in the new suit - singleton/void;
- three of the agreed suit - no singleton/void, 16+ HCP;
- 3NT - no singleton/void, 14-15 HCP;
- four of the agreed suit - 11-14 HCP, no singleton/void.
After the intervention of the opponents, the balance bid.