Modes and Cornerstones
1♥, 1♠, 1N, 2♣, and 2♦ are the Cornerstones (CS) bids of the system. With different modes (preceding sequences), CS bids show the same distributions with different strengths. Continuations are similar with some variations.
Shapes of CS Bids
The shapes of the 5 CS bids includes all possible shapes within a point range
- 1♥: 4+♥. Not 4333 / 4432. May have a longer minor
- 1♠: 4+♠. Not 4333 / 4432. May have a longer minor
- 1N: Balanced. May be 5M332 or 6m322 or 5422 both minors
- 2♣: 6+♣ or 5=♣ 4+♦. No 4-card major
- 2♦: 6+♦ or 5=♦ 4+♣. No 4-card major
When having both majors, opening the longer one, or the stronger one if equal in length.
Similarly, when having both minors, opening the lonfer one, or the stronger one if equal in length.
Sequences of Different Modes
Mode 0: CS
- CS bidder:
- (NV) 8-11 unbal / 10-13 Bal
- (Vul) 8-11 unbal / 14-16 Bal
- Partner: Any strength
Mode 1: 1♣ - CS
- CS bidder
- (NV) 8-11 unbal / 9-11 Bal
- (Vul) 8-11 unbal / 8-9 bal
- Partner
- (NV) 12-16 unbal / 14-16 bal
- (Vul) 12-16 unbal / 12-13 bal
- Same as Mode 0, except 1♣ - 1M; 3M is 5=M invite.
Mode 2: 1♣ - 1♦; CS
- CS bidder
- (NV) 12-16 unbal / 14-16 bal
- (Vul) 12-16 unbal / 12-13 bal
- Partner
- (NV) 0-7(8) or 12+ GF
- (Vul) 0-7 any, 10-11 bal, or 12+ GF
- Same as Mode 0, except the following
- Responder’s invite at or below 2N remains invite (by shape, not HCP)
- Responder’s invite above 2N becomes GF
Mode 3: P - CS
- CS bidder: 12-16 unbal / 14-16 bal
- Partner:
- (NV) 0-7 unbal or 0-9 bal
- (Vul) 0-7 unbal or 0-11 bal
- Same as Mode 0, except partner borrows 3 HCPs from the CS bidder
- P - 1M and P - 2m have different developments (Modified Drury and 2m passed responses)
Mode 4: P - 1♣; CS
- CS bidder: 5-7
- Partner: 17-19
- Same as Mode 1, except CS bidder borrows 3 HCPs from partner
Mode 5: P - 1♣; 1♦ - CS
- CS bidder: 17-19
- Partner:
- (NV) 0-4, or 8-9 bal
- (Vul) 0-4, or 8-11 bal
- Same as Mode 2, except partner borrows 3 HCPs from the CS bidder