21GF - 2/1 Game Force

Features:

After 1♣ opening, responder commonly skips long diamonds suit if he has a 4-M. So 1♣ - 1 = no 4-card major.


Opener’s second bid after game forcing bid:


Opener’s second bid after the forcing notrump 1 - 1NT:


Opener’s second bid after the forcing notrump 1♠ - 1NT: