Carrot 1NT

• 2♥/2♠ are natural weak (7-9) invitations with a 5-card major.
• 2NT is a strong (10-11) invitation, which may also contain 4-card major(s) (opener will only pass with 13-14, in which case he cannot have a 4-card major).
• 2♣ is Stayman on most other hands (7-9 weak invitational, or game-forcing strength) but is also used with a 5-card major and strong invitation, 10-11.
• 2♦ is a relay to 2♥ with sign-off hands or certain game-forcing hands.
• 3♣/♦ are natural invitation to 3NT with a long suit, 6-9. If minimum, the suit should have 2 top honors.
• 3♥/♠ are natural invitation with 6-card suit, 9-11.
• 3NT natural to play.
• 4♣/♦ are transfers to 4♥ and 4♠ ("South African Texas").
• 4♥/♠ natural to play.
• 4NT is Blackwood 4 Aces.

• Pass/2♠ = Sign-off in major.
• 2NT = New relay to 3♣ after which:
  • Pass/3♦ = Sign-off in minor.
  • 3♥/♠ = Game-force showing 3-card suit, singleton in other major, and 5-4 or 4-5 in the minors.
  • 3NT = 5-5 in the minors. Non-forcing with game-values.
• 3 of a suit = Natural slamtry with 6+suit.
• 3NT = Forcing slamtry with 5-5 or better in the minors.

Opener will only pass with 13-14 hcp, thus denying a 4-card major.

With 15-17, opener can bid a 5-card major naturally, 3NT to play with no major, or use 3♣ to ask for a 4-card major. Over 3♣, responder bids 3♦ with 4♥, 3♥ with 4♠ or 3NT without major.

• Double is negative, about 8-11 HCP, and forcing to 2NT (or penalty double).
• 2 of a suit is constructive to play or possibly mildly invitational.
• 2NT is Lebensohl-style and relay to 3♣. Responder can pass or correct to a suit lower than the overcall (or the suit overcalled, if overcall was artificial)