1♠ and 1♥ responses
The 1♠ and 1♥ responses always shows 4+ cards, usually 6~16 points. If the opened suit is void, these responses can be made with insufficient strength.
These responses are a major tool to find a major fit in a 5-card major system. They take care of situations where opener has no more cards than responder in a major. Although opener might still have a 5-card major which is blocked by a longer minor, these patterns are rare and hence temporarily neglected by responder.
Opener's rebids
The 2NT rebid is highly descriptive, so opener shall always consider this rebid first even if a major fit is found.
- 2NT
- 18~19 HCP, balanced or 2=2=5-4, possible major fit.
Thereafter, opener shall be eager to show a major fit. Failure to show a major fit denies 4-card support.
Found major fit
These rebids shows 4+ cards in the responded major. The partner will not play in another suit (but a notrump game is still possible).
- Simple raise (2-level)
- 13~16 points.
- Jump raise (3-level)
- Invitational, 17~19 points.
- Double jump to own suit (4-level)
- Fit-showing, 20+ points, 6+ cards.
- Double jump to new suit
- Splinter, 20+ points, 0~1 card.
- Double jump raise (4-level)
- 18~19 HCP, 5-4-2-2.
Major fit not found
By not bidding 2NT nor showing a major fit, opener denies a major fit. Opener has at most 3 cards in the responded major.
- Minimum
- Never bid over 2 of own suit.
- Medium
- Simply bid a new suit.
- Maximum
- Bid over 2 of own suit.
Opened 1♣
Opener always raises with 4-card support even at the last 2 seats to silence balancing overcalls.
- Pass
- Responder passed, 11~12 HCP, exact 3-card support.
- 1♠
- 13~18 points, 4+ cards.
- 1NT
- 12~14 HCP, balanced or 5-4-2-2, 2~3 spades.
- 2♣
- 13~18 points, 5+ cards, unbalanced.
- New suit 2♦ or 2♥
- Reverse, 18+ points, 4+ cards, unbalanced.
- Jump to 2♠
- SJS, 19+ points, 4+ cards.
- 3♣
- SJS, 19+ points, 6+ cards.
- 3NT!
- 18~19 HCP, 6-3-2-2 where the responded major is doubleton.
Opened 1♦
- Pass
- Responder passed, 11~12 HCP, exact 3-card support.
- 1♠
- 13~18 points, 4+ cards.
- 1NT
- 12~14 HCP, balanced or 5-4-2-2, 2~3 spades.
- 2♣
- 13~18 points, 4+ cards, unbalanced.
- 2♦
- 13~18 points, 5+ cards, unbalanced.
- New suit 2♥
- Reverse, 18+ points, 4+ cards, unbalanced.
- Jump to 2♠ or 3♣
- SJS, 19+ points, 4+ cards.
- 3♦
- SJS, 19+ points, 6+ cards.
- 3NT!
- 18~19 HCP, 6-3-2-2 where the responded major is doubleton.
Summary of rebidding strategy
This strategy also applies to 1♣-1♦, but there are different considerations between over 1♦ and over a major rebid, so they deserve different pages.
Minimum
There are strict requirements for 1NT to make it balanced and specific, enabling more evasion from 1NT with weak hands.
- Try to bid a major.
- Bid 1NT if balanced or 5-4-2-2.
- Bid a minor.
The tradeoff is that opener sometimes rebids a minor with short opened minor, but this situation shall not cause problems because bidding structure is unaffected.
Rebidding the opened suit usually shows 6+ cards, but only 5 cards with 5-4-3-1 or 5-4-4-0 where the 4-card suits is blocked. Responder may still pass to play the 5-2 fit.
The 1♦-1♠; 2♣ auction occcasionally contains only 4 diamonds due to 1=4=4=4. Responder still choose diamonds with equal preference because opener's diamonds is no shorter than clubs.
Medium
Bid a suit at the cheapest level. Opener must have an unbalanced hand and thus an eligible suit to bid, or 1NT would have been opened.
Maximum
- Bid 2NT if balanced.
- Show a major fit if present.
- Bid 3NT with 6-3-3-2 but avoid missing a 3-5 major fit.
- Bid a minor.