Precision Bidding System


This note is a summary of the Precision Bidding System that we are currently playing. The 1C: opening encompasses all 16+ HCP hands, except for the balanced 22-23 HCP hands opening 2NT. The system includes weak 1NT opening (13-15 HCP), five-card majors, natural 2C:, and mini-Roman 2D:. All bids marked * are forcing.

Opening Bids

Here is a brief overview of the Precision System's opening bid structure:
1C:* - Artificial, 16+ HCP, any distribution except for 22-23 HCP balanced hands.
1D: - 11-15 HCP, 3+ diamonds, no 5-card majors.
1H:/1S: - 11-15 HCP, 5+ card suit.
1NT - 13-15 HCP, no 5-card majors.
2C: - 11-15 HCP, either 6+ club suit or 5 club suit plus a 4-card major suit.
2D:* - 11-15 HCP, mini Roman. 4414 or 4405 with singleton or void in diamonds.
2H:/2S: - 7-10 HCP, 6+ suit, weak.
2NT - 22-23 HCP, balanced.
3C:/3D: - 8+ HCP, 7+ semi-solid suit.
3NT - Gambling, one 7+ solid minor suit.

Responses to 1C:

Strong 1C: structure is the most important part of the Precision system. The responses can be classified into three categories: (1) Negative, (2) Constructive, and (3) Positive.

(1) Negative

1D:* - 0-7 HCP, negative.
1D:* - Impossible negative - 8+ HCP, 4441 distribution. In rebid, responder either jumps in no-trump if opener bids his short suit; or jumps in his short suit if opener bids anything else.
After 1C: - 1D:
1NT - 16-18 balanced, may have 5 card minor
Pass - 0-4 HCP, balanced.
2C: - 5-7 HCP, Stayman
2D: - Jacoby transfer to hearts.
2H: - Jacoby transfer to spades.
2NT - 7 HCP, inviting 3NT.
Jump in new suit - Impossible negative, singleton in the bid suit.
4C: - Gerber.
4D:/4H: - Texas transfer to 4H:/4S:.
2NT - 19-21 balanced, may have 5 card minor.
Pass - 0-3 HCP
3C: - 4-7 HCP, Stayman
3D: - Jacoby transfer to 3H:
3H: - Jacoby transfer to 3S:
3S: - Jacoby transfer to minors
3NT - 4-5 HCP, balanced, sign-off.
4C: - Gerber.
4D:/4H: - Texas transfer to 4H:/4S:.
3NT - 24-26 balanced, may have 5 card minor
Pass - 0-4 HCP
4C: - 5-7 HCP, Baron, slam try
4D: - Jacoby transfer to hearts.
4H: - Jacoby transfer to spades.
4S: - Jacoby transfer to minors.
4NT - Quantitative.
1H:/1S: - maybe 4 card suit with another 5 card minor or only 5 card major.
Pass - 0-3 HCP.
Raise to 2H:/2S: - 4-7 points, including distribution
Raise to 3H:/3S: - 6-7 points, including distribution, 4+ card support.
Raise to 4H:/4S: - 8+ points, good distribution, 4+ card support.
1S: - 4-7 HCP, 5 card major.
1NT - 4-7 HCP with no support
2C:/2D: - 5-7 HCP, five card suit, non-forcing
2NT - Impossible negative.
2C:/2D: - 6 card suit or 5 card suit with weak major, or both minors.
Pass - 0-3 HCP.
2H:/2S: - 5+ card suit.
2NT - 5-7 HCP, scattered values, balanced.
2D:/3C: - 5-7 HCP, 6+ card suit
Single raise, non-forcing
3NT - Impossible negative, singleton in partner's suit
Jump to 2H:/2S:/3C:/3D: - 22+ HCP. 5 card suit.
Minimum NT - 0-3 HCP, minimum and no support.
Raise - 0-3 HCP, minimum and support
New suit - 4-7 HCP, values in the suit, no support to partner's suit
Opener's rebid - non-forcing
New suit - forcing
Double jump to 3H:/3S: - Ace-asking.
(2) Constructive
2H:/2S: - 4-7 HCP, 6-card suit; little strength outside.
Pass - Game unlikely.
Raise to game (including 3NT).
New suit* - forcing one round. Rebids:
Raise - 3+ support (or Qx).
Rebid H:/S: - minimum, no support.
Cue-bid under 3NT - singleton or void.
2NT* - support in suit, forcing
Rebid H:/S: - minimum
New suit - singleton or void in suit bid
3NT - suit with AQ or KQ
4NT - Blackwood.
3C:/3D:/3H:/3S: - 4-7 HCP, 7-card suit; little strength outside.
Pass - Game unlikely.
Raise to game.
New suit* - forcing one round. Rebids:
Raise - 3+ support (or Qx).
Rebid H:/S: - minimum, no support.
Cue-bid under 3NT - singleton or void.
4NT - Blackwood.
(3) Positive
1H:/1S:/2C:/2D:* - 8+ HCP, 5+ card suit, forcing to game unless both hands are minimum and no fit is found.
New suit* - 5+ card suit, forcing one round. Responder rebids:
8-10 HCP:
New suit - 4-card suit.
Rebid original suit - 6+ card suit, semi-solid for minors.
Raise - 3+ card support.
Minimum no-trump - 5332 distribution, values in unbid suits.
11+ HCP, 4+ controls (A=2 controls, K=1 control): Jump under 3NT.
New suit - 4-card suit.
Rebid own suit - 6+ card suit, semi-solid for minors.
Raise - 3+ card support.
1NT - 8-11 HCP, balanced, no 5 card suit
2C: - Stayman and relay for point range
2D: - 8-11 HCP, no major
2H:/2S: - 8-11 HCP, 4-card suit
Opener's 2NT rebid is non-forcing
New suit - 16-21 HCP, 5+ card suit.
Jump in new suit - 22+ HCP, 5+ card suit.
2NT - 11-13 HCP or 16+ HCP, balanced.
3C: - Baron
3D:/3H:/3S: - 5+ card suit
3NT - 14-15 HCP, balanced
4C: - Baron: modified Stayman asking responder to start bidding his 4 card suit starting from lowest
After interventions
Double -
Pass - 0-4 HCP
1D: - 5-8 HCP, no major
Suit - 5-8 HCP, 5+ card suit; without changes for constructive responses.
Redouble - 9+ HCP
At 1 level -
Pass - 0-4 HCP
Suit - 5-8 HCP, 5+ card suit
1NT - 6-8 HCP, with a stopper
2NT - 9-11 HCP, with a stopper
3NT - 12-14 HCP, with a stopper
Double - 5-8 HCP or 9+ HCP, takeout, with 9+ bid again (notrump or cuebid rebid shows no stopper)
Cuebid - 9+ HCP, short in overcall suit, forcing
1NT -
Pass - 0-4 HCP
Suit - 5-8 HCP, 5+ card suit
Double - penalty oriented
At 2 level -
Pass - 0-4 HCP or 9+ HCP with strength in opponents suit
Suit - 5-8 HCP, 5+ card suit
Double - 9+ HCP, optional
At 3 level -
Double - penalty oriented
After intervention to asking bids (P0D1):
Double - 1 step
Pass - 2 steps

Trump suit asking bids

After a 1C: opening and positive response in a suit, opener's direct single raise of partner's suit requests responder to define his trump holding. Responder rebids conventionally by steps:
1 step - No top honor
2 steps - 5 card suit, 1 top honor
3 steps - 5 card suit, 2 top honors
4 steps - 6 card suit, 1 top honor
5 steps - 6 card suit, 2 top honors
6 steps - 5+ card suit, 3 top honors

Asking for total controls (A=2 controls, K=1 control)

1 step - 0-2 controls
2 steps - 3 controls
3 steps - 4 controls
...

Control asking bids

After trump-asking bids, any new suit bid by opener is asking for holding in that suit.
1st step - 3 or more low cards (No control)
2nd step - Doubleton or Qxx (3rd round control)
3rd step - Singleton or Kx (2nd round control)
4th step - void or Ace (1st round control)
5th step - AK or AQ (Two top controls)
Any subsequent new-suit bid is also control-asking, the responses are now:
1 step - no control
2 steps - Singleton or Kx (2nd round control)
3 steps - void or Ace (1st round control)
4 steps - AK or AQ (Two top controls)

Responses to 1D:

Open 1D: with 11-15 HCP, 3+ card diamond suit.
Pass - 0-7 HCP.
1H:/1S:* - 8-15 HCP, 4+ card suit, forcing one round. 1S: denies 4-card H: suit.
11-13 HCP
1S: over 1H:, 4-card S: suit, denies 4-card H: suit.
1NT - sign-off
2C:* - fourth-suit forcing, "do something clever!".
1NT - Balanced, denies 4-card support.
2C:* - new-minor forcing, check-back.
2D: - 6+ card or good 5-card D: suit, no 4-card major.
2C: - unbalanced, 5-4 in minors, no 4-card major.
14-15 HCP
Double raise - 4-card support.
3D: - 6+ card D: suit, no 4-card major.
3C: - unbalanced, at least 5-5 in minors, no 4-card major.
1NT - 8-10 HCP, balanced, no major.
2C:/2D:* - Inverted minors, 11-15 HCP, 4+ card suit, forcing, responder denies a 4-card major. Opener rebids:
11-13 HCP
2H: - stopper in H:, no stopper in S:.
2S: - stopper in S:, no stopper in H:.
2NT - stopper in both majors.
2D:/3D: - no stopper in majors
14-15 HCP, forcing to game
3H: - stopper in H:, no stopper in S:.
3S: - stopper in S:, no stopper in H:.
3NT, stopper in both majors.
3C: - no stopper in majors
2H:/2S:/3C: - Jump shift 16+ HCP, game forcing, 5+ suit.
Raise - 3+ card support
3NT - 11-13 HCP, balanced, poor support
3D: - 11-13 HCP, unbalanced, poor support
New Suit - 4+ card suit, 14-15 HCP, poor support
Jump rebids D: - good 6 card suit
2NT* -
2NT (not a passed hand) - 16+ HCP, balanced
3C: - 11-13 HCP, unbalanced
3NT - 11-13 HCP, balanced hand
3D: - 14-15 balanced
3H:/3S:/4C:/4D: -- 14-15 HCP, unbalanced, 4+-card suit
2NT (passed hand) - 10-12 HCP, very strong support or style
3C: - asking for singleton
3D: - minimum opening 11-13 HCP
3D: - up to 10 HCP, preemptive; 5+-card support for diamonds
3NT - 14-15 HCP, balanced.
After intervention
Double:
2NT - 10-11 HCP, support in D:
3D: - 6-9 HCP, preempt
Redouble - 11+ HCP
Suite call up to 2S: level:
Double - 8-10 HCP, other 4-card major, negative
Suite call - 5-card suit for major
2D: - 6-9 HCP, support in D:
3D: - 10-11 HCP.
1NT - 8-10 HCP, balanced, stopper in opponent's suit
2NT - 11-13 HCP, balanced, stopper in opponent's suit

Responses to 1H:/1S:

Open 1H:/1S: with 11-15 HCP, 5+ card suit. Open 1H: denies 5 card S: suit.
Pass - 0-7 HCP, poor support.
2H:/2S: - Limited raise, 8-10 points, distribution points included, at least 3-card support.
3H:/3S: - trump suit game try
New suit - short suit game try
3C:/3D:/3H: after 1S:-2S:, singleton or void in the suit bid
2NT/3C:/3D: after 1H:-2H:, singleton or void in S:/C:/D: suit, respectively
2S:/2NT relay - ask partner relay to 2NT/3C:; help suit game try.
2NT (after 1H:-2H:-2S:) -
3C: - C: side suit
3D: - D: side suit
3H: - S: side suit
3C: (after 1S:-2S:-2NT) -
3D: - D: side suit
3H: - H: side suit
3S: - C: side suit
3H:/3S: - Limited jump raise, 11-13 points (distribution hand, no more than 11 HCP), 4-crad or good 3-card support, e.g., Qxx
4H:/4S: - 14+ HCP, 4-card or longer support (distribution hand, no more than 11 HCP).
1S:* (over 1H:)- 8-15 HCP, 4+ card suit
1NT - 11-13 HCP, minimum
2H: - 11-13 HCP, 6-card suit, non-forcing
2C:/2D: - 13-15 HCP, non-forcing
2S: - 11-13 HCP, 4-card support
2NT - 14-15 HCP, balanced, stoppers in remaining two suits
New suit at 3 level - 14-15 HCP, semi-forcing
3H: - good 6-card suit, at least AQJxxx
2C:/2D:/2H:* - 11-15 HCP, maybe 4 card minor suit but 5 card H: suit
Rebid 2H:/2S: - not necessarily a 6 card suit
Reverse in 2S: - 14-15 HCP, forcing
New suit at 2 level - may not be suit, 1 round force
2NT - 11-13 HCP, stoppers in remaining two suits
3C:/3D:/3H: - 11-13 HCP, good support, non-forcing
Jump in a new suit - 14-15 HCP, good support, control in suit
Jump in original suit - 14-15 HCP, very good 6 card suit
3NT - 15 HCP, stoppers in remaining suits
1NT* - 8-15 HCP, balanced hand with mild support for opener's suit or unbalanced hand with insufficient HCP to justify a 2-over-1 response:
11-13 HCP:
2C:/2D:/2H: - lower ranking 4-card suit, or better 3-card minor.
Rebids 2H:/2S: - 6 card suit
14-15 HCP:
Jump-rebids 3H:/3S: - 6 card solid suit (at least AKQxxx)
Reverses in a higher ranking suit
Jumps in second 5-card suit
2NT - 5-3-3-2 distribution.
Should responder then rebid a new suit, opener should pass but may raise with maximum and good 3-card support. If responder has high limit (12-15 HCP), he should bid the final contract directly.
Jump Shift* - 16+ HCP, game forcing, strong suit, or good support and fair suit
Raise - 3+ card support
3NT - 11-13 HCP, balanced, poor support
Rebids H:/S: - 11-13 HCP, unbalanced, poor support
New Suit - 4+ card suit, 14-15 HCP, poor support
Jump rebids H:/S: - good 6 card suit
2NT* -
2NT (not a passed hand) - 16+ HCP, balanced
3C: - 11-13 HCP, unbalanced
3NT - 11-13 HCP, balanced hand
3D: - 14-15 balanced
3H:/3S:/4C:/4D: -- 14-15 HCP, unbalanced, 4+ card suit
2NT (passed hand) - 10-12 HCP, very strong support or style
3C: - asking for singleton
3D: - minimum opening 11-13 HCP
3H:/3S: - sub minimum opening, 9-12 HCP
4H:/4S: - game call
Double Jump Shift* - Splinter, game forcing, singleton or void in suit to be bid, 4+ card support for opener, slam invitation.
4H:/4S: - to play
New Suit - Cue-bid Ace, slam try.
3NT - 14-15 HCP, usually 4-card support for opener's major, responder lacks a void or singleton in side suit. controls, no singleton or void minimum 4 controls, no singleton or void

After intervention

Double -
Raise - 4-7 HCP, preemptive, following the Law of Total Tricks
1NT - same as the single raise (2H:/2S:) without the double
2NT - same as the double raise (3H:/3S:) without the double
4H:/4S: - to play
Redouble - 11+ HCP
Suit Overcall -
Pass - 0-7 HCP or 8+ HCP and waiting for penalty if opener reopens with a double
Double - 7-9 HCP, 4-card suit in other major
1NT - 8-10 HCP, stopper in opponent's overcall suit
2NT - 11-12 HCP, stopper in opponent's overcall suit
Cue-bid - 15+ HCP, singleton or void in enemy's suit, forcing.

Responses to 1NT Opening

Open 1NT with 13-15 HCP, balanced hands. Only clubs can be 5 cards long.
2C: - 8-11 HCP, non-forcing Stayman.
2D: - no major
pass - garbage Stayman.
2H:/2S: - five card suit, inviting.
2NT - balanced with one four card major.
3C:/3D: - good but broken 6+ card suit, strongly inviting 3NT.
Jump to 3H:/S: - good but broken 6 card suit, asking for support, strongly inviting game.
2H:/S: - 4-card major (H: first if both majors)
Pass - garbage Stayman
2S: - five card suit, inviting.
2NT - balanced, with the other 4 card major.
3C:/3D: - good but broken 6+ card suit, strongly inviting 3NT.
Raise - inviting, four card support.
Jump to 3S: - good but broken 6 card suit, asking for support, strongly inviting game.
2D:* - 12+ HCP, game-forcing Stayman.
2H:/2S: - 4-card major (H: first if both)
3C:/3D: - 5-card minor suit
2NT - no 4-card major or 5-card minor
3C: - Relay asking for opener's distribution shown by:
3D: - 3343 only D: suit
3H: - 2344 both minor with 3 card H:
3S: - 3244 both minor with 3 card S:
3NT - 3334 only C: suit
2NT - 10-11 HCP, no major, no five card minor.
2H:/2S:/3C:/3D: - sign-off.
3H:/3S:* - one suited hand, game forcing
3NT - to play
Raise to game - with 3-card support
Cue-bid - slam try
4C: - Gerber. "Aces?"
4D:/H: - Texas transfer to 4H:/S:.
4NT - 17-18 HCP, balanced, quantitative.
6NT - 19-21 HCP, balanced.
5NT - 22-23 HCP, balanced, "Grand Slam Force".
After intervention
Double
Pass - weak, nowhere to escape; or 6-11 HCP balanced
Redouble - SOS, requesting partner to bid 2C:
2C:/2D:/2H: - ask partner relay to 2D:/2H:/2S:, respectively
2S: - forcing, 12+ HCP.
Suit overcall
Double - Penalty
2NT - Lebensohl; forcing partner to bid 3C:
Suit call at 2 level - 0-6 HCP, sign-off
Suit call at 3 level - 7-10 HCP, inviting (0-6 HCP uses Lebensohl)
3NT - Lebensohl, denies a stopper in enermy's suit; while using Lebensohl 2NT then bid 3NT promises a stopper, "the more you bid notrump the more stoppers you have".

Responses to 2C:

2C: Opener holds 11-15 HCPs and either 5+ clubs with a 4-card major or 6+ clubs.
2D:* - 11+ HCP, conventional and forcing (with C: fit, may be made with only 8 HCP). Opener rebids:
2H: - 11-13 HCP, 4-card H: suit
2S: - 11-13 HCP, 4-card S: suit
2NT - 11-13 HCP, 6322 balanced hand, 6-card C: suit, stoppers in two other suits.
3D:* - to request opener to clarify stoppers. Opener's rebids show:
3H:* - H: and D: suit
3S:* - S: and D: suit
3NT* - H: and S: suit
3C: - 11-13 HCP, 6-card C: suit, one other suit stopped.
3D:* - to request opener to clarify stoppers. Opener's rebids show:
3H:* - H: suit
3S:* - S: suit
3NT* - D: suit
3D:* - 5-card D: suit (6C:, 5D:).
3NT - 14-15 HCP, 6322 balanced hand, 6-card good C: suit.
3H: - 14-15 HCP, 4-card H: suit
3S: - 14-15 HCP, 4-card S: suit
3D:/3H:/3S: - Jump shift, 16+ HCP, good 5-card suit. Opener rebids:
3NT - less than 2-card support
Simple raise - minimum, 3-card support
New suit - maximum, 3+ card support, cue-bid Ace, slam try.
2H:/2S: - 8-10 HCP, non-forcing, invitational. Opener may pass with minimum and mild support.
2NT - 10-11 HCP, invitation to 3NT.
3C: - 8-10 HCP, 3+ card C: support, non-forcing, denies 5-card majors. Opener may pass with minimum, try 3NT with maximum.
After intervention
Negative doubles through 2S:
Redouble - 10+ HCP
Cuebid - 12+ HCP

Mini-Roman 2D:

Open 2D: with 11-15 HCP, singleton or void in D:, no 5 card major (4414 or 4405).
Pass - 0-7 HCP, 6 card D: suit
2H:/2S:/3C: - 0-7 HCP, minimum 4 card support, sign-off
2NT* - 8+ HCP, forcing one round, asking for strength and pattern
3H: - 11-13 HCP, 4414
3S: - 14-15 HCP, 4414
3C:/4C: - 11-13 HCP, 4405
3H:/3S: - non-forcing
3D:/4D: - 14-15 HCP, 4405
3H:/3S: - non-forcing
3NT - 14-15 HCP, 4414 with D: A or K singleton
3C: - 0-7 HCP, 4 card suit or 3 card suit with no 3 card suit H: or 4 card suit S:
3D: - 11-12, very good 6 card suit D:
Pass - void in D:
3H:/3S: - good suit, minimum singleton D:
After intervention
Suit call -
Double - Penalty
2NT/3D:* - the same as 2NT asking above
Cuebid - 12+ HCP, forcing
Double/3D:
Redouble - the same as 2NT asking above
3 of a suit - 9-11 HCP, non-forcing

Responses to 2NT Opening

Open 2NT with 22-23 HCP and a balanced hand. 2NT Opener may have a minor five-card suit.
3C:* - Baron.
3D: - Jacoby transfer to hearts. Often done with 5 hearts.
3H: - Jacoby transfer to spades. Often done with 5 spades.
3S: - Minor suit sign-off or slam try. Opener rebids:
3NT - D: preference or, at least, no distinct C: preference
4C: - C: preference
Responder can cuebid a major to try for slam.
4C: - Gerber. "Aces?"
4NT - Quantitative.

Gambling 3NT

Opener begins with 3NT with a solid 7+ card minor suit. Opener promises one outside stopper only if vulnerable. In first or second seat 3NT opener denies a void but may well have a singleton.
4NT - Quantitative. "8th card in the long minor?"
4C: - "Pass or bid your suit (if not clubs)."
4D: - "Short suit?"
If Responder, after asking for a short suit, bids 5NT - a "Grand Slam Force" of sorts - he is, in fact, asking for a 8th card in the long suit. 3NT Opener rebids 6-of-his-suit with 7-card length, 6H: or higher with 8-card length.

Preemptive Opening Bids

2H:/2S: - 7-10 HCP, good 6 card suit, no second major, no void, RONF (Raise is the Only Non-Forcing bid)
New Suit - 11+ HCP, good suit, inviting support, one round force
2NT - 12+ HCP, game likely, relay asking for singleton or void
Suit -Feature, usually a singleton or a void
3NT - Solid 6+ card suit
3H:/3S: - No feature
Raise to 3H:/3S: - pre-emptive
Jump to 4H:/4S: - maybe preemptive, maybe strong, no slam likely
3NT - to play
3C:/3D:/3H:/3S: - 7-11 HCP, 7 card semi-solid suit, Rule of 2 and 3
New Suit - forcing 1 round
Others - Natural
Raises - Pre-emptive

Competitive Bidding

Overcall
1 over 1 - 7+ HCP; 2 over 1 - 9+ HCP - very good suit, watch out the vulnerability!
Raise - 7+ HCP, preemptive
Double Raise - Pre-emptive
Cue-bid - 9+ HCP with support; 11+ HCP if raised next round
Jump in a suit - weak, 6+ card suit
Raise - 7-8 HCP with fit (xxx or doubleton honor)
Cue-bid - 9-11 HCP with support
Michael's Cue-bids
14+ HCP, at least 5-5 in two higher unbid suits
Unusual 2NT
2NT - 11+ HCP, with 5-5 in 2 lowest unbid suits, "LOTUS" (lower of two usually stronger).
Defending 1NT
Double - 16+ HCP for weak 1NT (10-12 HCP, 12-14 HCP, or 13-15 HCP), penalty oriented; 13+ HCP for strong 1NT (15-18 HCP), an unnamed good suit, ask partner to bid 2C:
2C: - 11+ HCP, 5-card C: suit plus a 4+ card major suit
2D: - 11+ HCP, majors (at least 9 cards, usually 5-5)
2H:/2S: - 9+ HCP, natural, 6+ card suit or good 5 card suit.
2NT - unusual 2NT (5-5 in both minors), LOTUS is off
Weak 2 of a suit:
Double - 13+ HCP, shortness in opener's suit, 16+ HCP if taken a second bid. Lebensohl is on in the response
2NT - Lebensohl
3C: - Double was takeout
Suit lower in rank than the preempt suit - 0-6 HCP, signoff
Suit higher in rank than the preempt suit - 7-10 HCP, inviting
3NT - Slow Lebensohl, promise a stopper in enermy's suit, "the more you bid notrump the more stoppers you have".
Reject the relay, new suit - Double was power double (16+ HCP), 5+ card suit
3NT - to play
3NT - denies a stopper in enermy's suit, "the more you bid notrump the more stoppers you have".
Suit - 13+ HCP, good suit
Weak 3 of a suit
3C:/3D:
Double - 16+ HCP, support for both majors
3H:/3S: - 16+ HCP, maybe 4 card suit with a longer minor
Cue-bid - 10+ HCP, asking for better suit if any
Double - 8+ HCP, moderate support
3H:/3S:
Double - 16+, with second major
Weak 4 of a suit
4C:/4D: -
Double - 16+ HCP, for penalty with quick tricks
4H: -
Double - 16+ HCP, tolerance for S:

Balancing

Over a suit bid at one level -
Minimum suit bid - 8-13 HCP, usually a 5+-card suit (but may be a good 4-card suit at the one-level). The better your suit, the fewer pts. you need to bid.
1NT - 11-15 HCP (vulnerable 13-16 HCP), with stoppers (or moderate length) in the opponents' suit.
A jump in a new suit - 13-16 HCP, a strong 6+-card suit.
Double - takeout, 10-14 HCP or 15+ HCP, with shortness in the opponent's suit (with 15+ HCP bid again)
Cuebid - Micheal's cuebid, 14+ HCP
2NT - Unusual, showing length in the two lower unbid suits.
Over an opening 1NT - see defending 1NT (the same)
Opponents stop in 1NT - some extra strength to balance over these auctions
Opponents stop in a part score -
Double - takeout
Suit bid - A one-suited hand that doesn't have the right pattern for a takeout double.
2NT - Unusual, showing length in the two lowest unbid suits (usually the minors).

Doubles

Direct double over opponent's opening - either 13-15 HCP (takeout), or power double (16+ HCP).
Takeout - over minor the takeout double usually promises 4 card suit in both majors, over opponent's major opening promises 4+ card in the other major.
Response is requested even with 0 HCP. Pass indicates a long and solid suit the opponent bid.
Freebid after opponents bid
1 level - 5-8 HCP
2 level - 7-11 HCP
3 -level - 9-13 HCP
1NT - 8-10 HCP, a stopper in opponent's suit
Jump - 9+ HCP
Power double - Rebids or raises after the double, 16+ HCP.
Negative double - through 2S:
Double opponent's intervention - 8-15 HCP at 1 level; 11-15 HCP at 2 level. Over opponent's overcall in major promises a 4-card other major (direct suit bid indicates 5+ card suit).
Responsive Double - Double in competitive auctions indicates a 3 card support of partner's suit.

Lightner Double - Requesting a unusual opening lead against enemy's slam contract.

Takeout or Penalty? - Double is for penalty if
- Our side has agreed a suit
- Our side has pre-empted
- Our side has bid natural no-trump
- When one partner has defined his shape (e.g., rebid a suit)
- Our side has redoubled

Copyright © 1997 Xiao-Qian Wang