Update history

Recent updates:

• After 1M > (1NT), 2NT is 10-12 M supp (link).
• After 1H > 2m, with 5431 (4 spades and short in m'), bid 2NT (link).
• After 1H > 1NT > 3H and 1S > 1NT > 3S, other major = 10-12 3-card supp (link).
• After 1H > 1S > 2H, bid 3C with 9-12, 4 spades, 0 heart (link).
• 1H > 3m = 13+, 4 spades, 0 heart (link).
• After 1M > 2NT, 3C=55M, 3D=65M, 3M to play, 3M' (other M) 6-card opening M GF (link).
• 1m > 2H > 2S is F1 (may have 1 heart) (link).
• After 1m > 2M, new suit at 3-level shows void in M, non-forcing (link).
• It has been clarified that after 1m > 2m > 3m, new suit is stopper asking (link).
• 2NT opening can have 5M/6m, 3NT opening can have 6m but not 5M (link).
• After (1NT) > X, system may now be ON depending on the strength of (1NT) (link).

Old updates:

• 1NT > 2C > 2D > 3m now shows shortness in a corresponding major, and some shortness-showing convention has been updated (link).
• A major after 1D > 2C is now stopper-asking instead of stopper-showing (link).
• It has been clarified that the DORA rule also applies to opponent's redoubles, in an even more restrictive way (link).
• The invitational double convention has been added (link).
• The unusual suit convention after 1M > 1NT > 2M has been added (link).
• 1S > 3C/3D/3H now shows hearts, 0-1 spade and 9-12 points (link).
• The takeout double convention has been updated, clarifying jump rebids and raises; also a double of (4m)/(4H) opening is now for takeout (link).
• The NMF convention has been updated (link).
• The unusual suit convention has been added (link).

Very old updates:

• It has been clarified whether (1S) > 2C > (X) > XX constitutes a negative redouble (link).
• It has been clarified that bidding opponent's minor can sometimes be natural (link).
• It has been clarified that with no major fit, bidding a major either shows or asks for stopper, depending on the bidding (link).
• It has been clarified that after 1NT is interfered, an NT rebid should promise stopper in opponent's suits; values without a stopper are shown by a cue bid (link).
• The I-DO system after 1NT/2NT is now used up to 2S/3S instead of 2H/3H (link).
• It has been clarified that the count signal should be shown when ruffing and when it was not previously shown (link).
• It has been clarified whether the sequence opening > (overcall) > X > (response) > X constitutes a support double (link).
• A 4C opening now shows a 28+ balanced hand (link).
• It has been clarified that after (weak 2) > 2NT or (multi-2D) > 2NT, the 2NT opening system is ON (link and link).
• Bids when faced with various (2-level) openings have been added (link).
• It has been clarified that after (1NT) > X, the 1NT opening system is OFF (link).
• 1S > 2H now shows 5+ hearts instead of 4+, and the subsequent developments are revised (link).
• The unusual 2NT convention has been added; (1X) > 2NT no longer shows 20-21 points with a balanced hand (link).
• Bidding against opponent's use of Michael's cue bid has been added (link).
• It has been clarified that NMF is OFF for a passed hand (link).
• The statement concerning bidding after 1M > (1NT) has been revised (link).
• It has been clarified that when responder has 5-5 in majors opposite a 1m opening, the sequence 1m > 1H > 1NT/2m > 2S is generally F1 (except for opener minimum) while 1m > 1H > 1NT/2m > 3S is GF (link).
• Jump to a new suit after weak-2 opening is now HSST. A strong hand should be shown by bidding a new suit after Ogust (link).
• The new minor forcing (NMF) convention has been added (link).
• Responses of the form 1m > 2M are now clarified to show 6+ cards and is F1 (link).
• Developments after weak-3 opening have been added (link).
• The help suit game try (HSGT) convention has been added (link).
• 1NT > 3C > 3D > 3NT now shows shortness in clubs (link).
• The Blackwood convention following a 2C > 2D opening has been revised (link).