pass after doubleNatural, nothing to say.
redoubleStrong and unbalanced, shows interest in doubling the opponents for penalties and likely to hold values in any suit that partner has denied with their 1NT response.
2CClub fit, natural
Rebid6-card suit, denies en route second suit unless at least 7-4 shape.
2HNatural (even if the opposition have overcalled in the suit), unbalanced, reversing strength
2SNatural (even if the opposition have overcalled in the suit), unbalanced, reversing strength
2NTGame-forcing, unbalanced.
3CClub fit, reversing strength
Jump rebidGood 6-card suit, at least reversing strength. Any continuation over this by responder in an uncontested auction is game-forcing.
Jump shift above reverseClub fit, game-forcing splinter
3NTTo play, with either: (a) a long running diamond suit, or (b) an extremely strong 4441 with a singleton club and no other rebid.
4 of a minorMinorwood
Game-level rebidGood 7-card suit (missing at most one of the top four honours) that would be (a) happy in game opposite a void and (b) good for grand slam opposite that missing singleton honour. However the hand's nothing special in terms of high cards, probably 12-14 points or so.
4NTquantitative invitation to 6NT
5Cto play
Jump shift to Blackwood LevelExclusion Blackwood
5NTquantitative invitation to 7NT
Jump shift to Grand-Hunting LevelComplete two-suiter. If the partnership had previously bid more than one suit and so there's ambiguity about which suits are being promised, then the other one is the first-bid suit of the player who just jumped.
Any slamNo systemic agreement; the natural interpretation
Copyright 2015 Finn Clark.