Standard American Yellow Card allows opening notrump with all balanced hand, even with a 5-card suit. It uses the following conventions with notrump openings:
After a 1NT Opening Edit
A 1NT opening promises 15-17 points and a balanced hand (at most one doubleton). The responses are:
- 2♣ is Nonforcing Stayman.
- 2♦ and 2♥ are Jacoby transfers to 2♥ and 2♠, respectively.
- 2♠ is a minor suit bust transfer to 3♣ (correctable to 3♦) showing a minor suit bust (6+ card suit, 0-8 points). Opener must pass afterwards.
- 2NT is invitational (8-9 HCP) and shows a balanced hand.
- 3♣ and 3♦ are natural, showing 6-card suits (with 5-7 HCP in the suit) and are invitational to 3NT.
- 3♥ and 3♠ are natural, showing 6-card suits and slam interest. Otherwise, a transfer is used.
- 3NT is a sign off in game.
- 4♣ is Gerber.
- 4NT is a Quantitative slam invite.
Nonforcing Stayman Edit
1NT-2♣ is nonforcing Stayman. Opener must bid the cheapest 4-card major at the 2-level, or 2♦ otherwise. With 4-4 in the majors, bid 2♥. After that, a 3 level minor shows 5 card suit and slam interest, but other continuations are undefined in the booklet.
Jacoby Transfers Edit
Responder's rebids Edit
- Pass: to play
- 2NT: invitational (8-9 HCP and exactly 5 trump). Opener chooses between 2NT, 3 of the suit, 3NT, or 4 of the suit.
- new suit: natural and game forcing, shows two-suited hands.
- single raise: invitational and shows six trump.
- 3NT: game choice. Pass or correct to 4 of the suit.
- raise to game: sign off, requires six trump.
Bypassing the transfer Edit
With a maximum (17 points) and four trump, opener may bypass the transfer, bidding responder's suit at the 3-level instead.
Gerber is completely identical to the standard. 4♣ asks for aces, after which 5♣ asks for kings. This is true after an 1NT or 2NT opening.
Quantitative Raise Edit
1NT-4NT is natural and invites 6NT.
Interference after 1NT opening Edit
After 1NT opening is doubled Edit
All responses are on after opponent doubles the opening.
After 1NT opening is overcalled Edit
Interference after a convention Edit
All rebids after interfered conventional responses are the same as without interference. Additionally,
- Opener may pass without support for responder's trump suit, since responder may bid again.
After a 2NT opening Edit
- 3♣ is Stayman.
- 3♦ and 3♥ are Jacoby transfers to 3♥ and 3♠, respectively.
- 4♣ is Gerber.
- 4NT invites 6NT.
After a 3NT opening Edit
3NT opening shows a 25-27 balanced hand.