mysterian

If you play a convention called Parker, you have a way to show minimum or maximum 6-4s when the suits are spades and hearts. Opener starts with One Spade, responder bids One Notrump (forcing), opener rebids 2H (with any hand that's less strong than a jump shift (18+). With the example hand, responder would rebid 2NT. Now the convention takes over. If opener rebids 3S he is 6-4 with a minimum. If he rebids 3H, he is 5-5 with a minimum. Both are non-forcing. If he rebids 3C, forcing 3D, he is about to bid 3S (forcing) with 6-4 or 3H (forcing) with 5-5. These sequences are forcing to game. So whenever opener is 6-4 he almost always rebids 2H over responder's One Notrump.