One Diamond Bidding System
One Diamond Bidding System
Open bidding
1. 1C 17 to 21pts, rebid NT, balance hand, 18-19pts
2. 1D 12 to 16pts, no 5 card majors. Rebid 1) 2C/2D >= 5 cards, 2) 2H/2S 4 card majors
3. 1H/S 12 to 16pts, >= 5 cards
4. 1NT:15-17pts, balance hand, can have one 5 card minor
5. 2C >= 22pts, or special hand with 9 winner tricks
6. 2D/H/S weak open, 5-11pts, 6 card suit. 2NT Ogust Responses
7. 2NT: 20-21pts, balance hand, can have one 5 card minor
8. 3C/D/H/S weak open, 6-10pts, 7 card suit
9. 3NT: 25-27pts, balance hand
10. 4C/D/H/S weak open, 6-10pts, >= 8 card suit, <= 1A
11. Third and fourth position open. 1D/H/S 10-16pts
12. Fourth position open. 2D/H/S 9-11pts, 6 card suit
Overcall: 1) one over one, >= 8pts, >= 5 cards; 2) Two over one, 11-16pts, >= 5 cards; 3) jump bid new suit, <= 10pts, >= 6 cards; 4) 1NT: 15-17pts.
Overcall: 5) Cue bid >= 17pts, singleton or void, for 1st round bid at any situation
Double: >= 12pts, rebid new suit >= 17pts; partner response 1) >= 4 card majors; 2) 5 card minors
Double: >= 12pts, 1) partner response, rebid NT >= 12pts balance hand; 2) opponent overcall, partner no response, rebid NT >= 18pts balance hand
Conventions: 1) Splinter Bids, singleton or void; 2) Cue bids，first round control, then second round control; 3) Blackwood for No-trump, 0-4, 1, 2, 3 (NT open, 4C ask A); 4) Trump 4NT, Five Keycard A Asking System for suit trump (5C: 0/3, 5D: 1/4, 5H: 2 without Q, 5S: 2 with Q)
2D/2H/2S weak open,response 2NT(Ogust Responses), rebid 3♣：minimum points, poor suit; 3♦：minimum points, good suit; 3♥：maximum points, poor suit; 3♠：maximum points, good suit. 1) Minimum points: 5-8 HCP 2)Maximum points: 9-11 HCP 3)good suit: 2 of top 3 (AKQ)
Fourth position 2D/2H/2S weak open, response 2NT(Ogust Responses), rebid 3♣：minimum points, poor suit; 3♦：minimum points, good suit; 3♥：maximum points, poor suit; 3♠：maximum points, good suit. 1) Minimum points: 9-10 HCP 2)Maximum points: 11 HCP 3)good suit: 2 of top 3 (AKQ)
Welcome Signals, 1)trump, big card welcome, 2) no-trmp, small card welcome,
Discard Signal, after void, use lo-lo, hi-hi signal; discard small card (<= 7) to ask partner to return lower suit from other two suits, discard big card (>= 8) to ask partner to return higher suit from other two suits
For no-trump, indicating opening lead double, 1) lead next opponent bidding suit; 2) if bidded two suits, lead second suit.
1NT open, opponent overcall, partner double = opponent bid, e.g. 1NT-2C-double, partner means 2C stayman, also for all others.
Alternative bid
1) bid new suit, force, a) maybe 2nd suit 2) maybe not 2nd suit, just force, has extra points, ask partner to bid extra if has.
1a) bid new suit, not-force for 1D-1H-1S/2C/2D, just want to play 1S/2C/2D, responder may bid 2C/2D/2H/2S and it will be final bid and play.
2) later cue bid, force, a) asking stopper, if have two stoppers, bid NT; 2) just force, partner bid 2nd suit if no stoppers