A 1NT or 2NT opening bid is well defined and allows responder to instantly decide whether their ambitions are limited (a weak hand), game invitational, a force to game, slam invitational, or a force to slam.
Generally a 4-4 major fit will play better than no trump, so some of our responses are designed to discover whether we have a major fit. When we have a longer major, we show this and allow partner to make the decision by using transfer responses.
A ‘transfer’ is a bid in a suit, telling partner to bid another suit. It is normal that the transfer-suit is one below the suit required to be bid by partner. We shall consider ‘red suit transfers’ as distinct from full transfers – the major difference being in the meaning of the 2S bid (from http://www.bridgewebs.com/porthcawl/TRANSFERS%20RED%20SUIT%20OVER%201NT.htm)
There are two good articles by Bernard Magee I recommend for players new to transfers:
https://mrbridge.co.uk/assets/docs/library/articles/bidding/Transfers_1.pdf
https://mrbridge.co.uk/assets/docs/library/articles/bidding/Transfers_2.pdf
We play the same responses after a strong 1NT overcall in 2nd [(1X) – 1NT] and 4th (live) [(1X) – P – (1Y) – 1NT] position, and after a balancing 1NT [(1X) – P – (P) – 1NT].
2C Stayman, asking for a 4-card major
2D Transfer to hearts, showing 5+ hearts
2H Transfer to spades, showing 5+ spades
2S Transfer to weak minor
2NT Invitational without a 4-card major
3X Natural, 1-suited slam try
3NT To play
4C Gerber, asking for aces
4D 5-5 majors, no slam interest
4H, 4S Natural, to play
4NT quantitative, inviting opener to bid 6NT with a maximum
Transfers and Stayman are OFF if the opponent doubles 1NT for PENALTY, so bids are NATURAL. Responder can REDOUBLE if they think 1NT will make.
If they double a transfer bid, then pass denies support, redouble suggests playing in the transfer suit, and other bids are unchanged.
We play the same responses after a strong 2NT overcall (e.g., (2H) – 2NT and (1H) – Pass – (Pass) – 2NT), after a 2NT rebid following a 2C opener and negative response (2C – 2D – 2NT) but not after a positive response.
3C Stayman
3D Transfer to hearts, showing 5+ hearts
3H Transfer to spades, showing 5+ spades
3S Minor-suit Stayman
3NT To play
4C Gerber
4D 5-5 majors, no slam interest
4H, 4S Natural, to play
Stayman is used with the following hands:
1NT 2C
2D 2NT is invitational, may have five spades and four hearts (can bid 3S w/ three spades if
accepting)
3C is game-forcing and shows a 5+ club suit and concern about 3NT (if 5 clubs then 4cM)
3D is game-forcing and shows a 5+ diamond suit and concern about 3NT (if 5 then 4cM)
3H is game-forcing shows FOUR hearts and FIVE spades (so that opener can play a 5-3 spade
fit)
3S is game-forcing shows FOUR spades and FIVE hearts (so that opener can play a 5-3 heart
fit)
1NT 2C
2H 2S is invitational with five spades and four hearts
2NT is invitational with four spades
3C is game-forcing and shows a 5+ club suit and concern about 3NT (if 5 then 4S too)
3D is game-forcing and shows a 5+ diamond suit and concern about 3NT (if 5 then 4S too)
3H is invitational
3S is a cue bid agreeing hearts, slam interest
3NT is to play, implying four spades (opener can pass, cue bid (max) or bid 4S holding 4
spades)
4C, 4D are cue bids agreeing hearts, slam interest
4H is to play
4NT is quantitative (implying four spades)
1NT 2C
2S 2NT is invitational with four hearts
3C is game-forcing and shows a 5+ club suit and concern about 3NT (if 5 then 4H too)
3D is game-forcing and shows a 5+ diamond suit and concern about 3NT (if 5 then 4H too)
3H is a cue bid agreeing spades, slam interest
3S is invitational
3NT is to play, implying four hearts
4C, 4D are cue bids agreeing spades, slam interest
4S is to play
4NT is quantitative (implying four hearts)
Major suit transfers are used with the following hands:
1NT 2D
2H Pass weak hand with 5+ hearts
2S invitational with five hearts and four spades
2NT invitational with five hearts
3C game-forcing with 5+ hearts and 4+ clubs
3D game-forcing with 5+ hearts and 4+ diamonds
3H invitational with 6 hearts
3S cue bid setting hearts as trumps, slam interest
3NT choice of game showing five hearts
4C, 4D cue bid setting hearts as trumps, slam interest
4H to play (no slam interest)
4NT quantitative
1NT 2H
2S Pass weak hand with 5+ spades
2NT invitational with five spades
3C game-forcing with 5+ spades and 4+ clubs
3D game-forcing with 5+ spades and 4+ diamonds
3H 5-5 majors with slam interest
3S invitational with 6 spades
3NT choice of game showing five spades
4C, 4D cue bid setting spades as trumps, slam interest
4H cue bid setting spades as trumps, slam interest
4S to play (no slam interest)
4NT quantitative
Transfer breaks
Opener can ‘break’ the transfer with 4-card support. After the transfer break, responder can ‘retransfer’ so the suit below is NEVER used as a transfer break.
Following a transfer break, responder can retransfer and then pass with weak hands or raise with hands not interested in slam. Other suit bids are natural or cue bids.
1NT 2D
2H Normal acceptance of transfer showing 2 or 3 hearts
2S, 3C Shows 4-card heart support and a good 4-card suit
2NT Shows 4-card heart support and a good 4-card DIAMOND suit
3H Four-card heart support with nothing else worth showing
1NT 2D
Break 3D retransfer, asking opener to bid 3H (either to pass or raise)
1NT 2H
2S Normal acceptance of transfer showing 2 or 3 spades
2NT Shows 4-card spade support and a good 4-card HEART suit
3C, 3D Shows 4-card spade support and a good 4-card suit
3S Four-card spade support with nothing else worth showing
1NT 2H
Break 3H retransfer, asking opener to bid 3S (either to pass or raise)
Competition
Transfers and Stayman are off if the opponent doubles 1NT, so bids are natural. If the 1NT opener redoubles a penalty double, this shows a 5-card suit and invites rescue.
If they double a transfer bid, then pass denies support, redouble suggests playing in the transfer suit, and other bids are unchanged.
1NT Pass 2D Dbl
Pass denies 3+ hearts
Rdbl denies 3+ hearts, probably 5-6 diamonds
2H 3-card heart support
2S, 2NT Transfer breaks
3C Transfer breaks
Minor suit transfer is used with a weak 1-suited minor hand, typically a six-card suit. Opener bids 3C and responder passes or bids 3D to play.
In competition,
1NT Pass 2S Dbl
Pass 5 spades, possible contract
3C pass or correct to 3D
2NT Responses
We play the same responses after a strong 2NT overcall (e.g., (2H) – 2NT and (1H) – Pass – (Pass) – 2NT), after a 2NT rebid following a 2C opener and negative response (2C – 2D – 2NT) but not after a positive response.
3C Stayman
3D Transfer to hearts, showing 5+ hearts
3H Transfer to spades, showing 5+ spades
3S Minor-suit Stayman
3NT To play
4C Gerber
4D 5-5 majors, no slam interest
4H, 4S Natural, to play
Stayman is used with the following hands:
2NT 3C
3D 3H is game-forcing shows FOUR hearts and FIVE spades (so that opener can play a 5-3 spade
fit)
3S is game-forcing shows FOUR spades and FIVE hearts (so that opener can play a 5-3 heart
fit)
4C is game-forcing and shows a 5+ club suit and slam interest
4D is game-forcing and shows a 5+ diamond suit and slam interest
2NT 3C
3H 3S is a slam try agreeing hearts (it is the only slam try available and is not a spade cue bid)
3NT is to play showing four spades
4C is game-forcing and shows a 5+ club suit and slam interest
4D is game-forcing and shows a 5+ diamond suit and slam interest
4H is to play
2NT 3C
3S 3NT is to play showing four hearts
4C is game-forcing and shows a 5+ club suit and slam interest
4D is game-forcing and shows a 5+ diamond suit and slam interest
4H is a slam try agreeing spades (it is the only slam try available and is not a heart cue bid)
4S is to play
Major suit transfers are used with the following hands:
2NT 3D
3H 3S cue bid, slam interest
3NT choice of game
4C game-forcing with 5+ hearts and 4+ clubs
4D game-forcing with 5+ hearts and 4+ diamonds
4H to play
2NT 3H
3S 3NT choice of game
4C game-forcing with 5+ spades and 4+ clubs
4D game-forcing with 5+ spades and 4+ diamonds
4H 5-5 majors, slam interest, FORCING to 4NT
4S agrees spades, FORCING, now 4NT Blackwood and cue bids
4NT sign off (probably 2-2 majors or no interest in slam)
5C cue bid agreeing hearts
5D cue bid agreeing hearts
5H heart preference
Transfer breaks
Opener can ‘break’ the transfer with 4-card support. After the transfer break, responder can ‘retransfer’ so the suit below is NEVER used as a transfer break.
2NT 3D
3H Normal acceptance of transfer showing 2 or 3 hearts
3S, 4C Shows 4-card heart support and a good 4-card suit
3NT Shows 4-card heart support and a good 4-card DIAMOND suit
4H Four-card heart support with nothing else worth showing
2NT 3D
Break 4D retransfer, asking opener to bid 4H (no slam interest)
2NT 3H
3S Normal acceptance of transfer showing 2 or 3 spades
3NT Shows 4-card spade support and a good 4-card HEART suit
4C, 4D Shows 4-card spade support and a good 4-card suit
4S Four-card spade support with nothing else worth showing
Competition
2NT Pass 3D Dbl
Pass denies 3+ hearts
Rdbl denies 3+ hearts, probably 5 diamonds
3H 3-card heart support
3S, 3NT Transfer breaks
4C Transfer breaks
Minor-suit Stayman
Minor suit Stayman is used on hands with at least 4-4 in the minors and promises slam interest.
2NT 3S
3NT no 4-card minor-suit
4C 4+ clubs
4D 4+ diamonds
4NT no fit, maximum, invitational
2NT 3S
3NT 4C shows 5+ clubs and slam interest (4NT is no fit or interest, suits are cue bids)
4D shows 5+ diamonds and slam interest (4NT is no fit or interest, suits are cue bids)