• Quite a lot of jump responses promise a trump fit with partner, including some which one might not expect to in a non-game-forcing auction.

  • pass after doublePartial support for partner's suit, e.g. three after 1S 2D, or a doubleton after 1S 2H.
    redoubleNot even partial support for partner's suit, either a singleton or doubleton. However not a void, because partner might gamble to play in the redoubled contract. Says nothing about strength, since the partnership is known to have at least game-going values.
    RebidNatural, denies en route second suit.
    New suitNatural (even if the opposition have overcalled in the suit), unbalanced.
    ReverseNatural (even if the opposition have overcalled in the suit), reversing strength, unbalanced.
    Raise4-card support
    2NT12-14 balanced. If the opening bid was 1S then opener is unlikely to have hearts as well, because we open 1H on a 12-14 4432 with both majors.
    Jump rebidReversing strength, single-suited with a good six-card suit and denying support for partner.
    Jump raiseMinorwood
    Unnecessary jump shift up to Splinter LevelSplinter, agreeing partner's trump suit and showing a small singleton or void. Splinters are normally game-forcing, but if two of them were available then the lower is merely invitational, e.g. 1C 1S 3D/4D are both splinters, since 1C 1S 2D would have been a reverse.
    Jump shift at splinter levelSplinter in support of partner's suit, purely shape-showing, neither confirms nor denies extra high-card strength.
    3NTBased on a long, solid suit, i.e. akin to the equivalent bid had the opening bid instead been one of a minor. Shows a hand with lots of tricks off the top (seven or eight if partner is weak). Any continuation except four of opener's suit is investigating slam.
    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.
    4NT5-card support, 4 Key Cards. It's absolutely not Blackwood, since there's unlikely to be any such need for precipitate action. With a hand that wants to bid Blackwood, you'll just have to make a quiet waiting bid and see what partner does next.
    Jump raise to 5Showing a trump fit (obviously) and all the key cards, i.e. all four aces and the king of trumps, which is already 19 points without even considering the rest of the hand. The advantage of this bid is that it bypasses a Blackwood bid that neither partner would have wanted to say. Your hand obviously has no interest in asking for key cards, while conversely your partner would have probably been nervous of doing so, having none himself. Further continuations (if any) are cue-bids, looking for a grand slam.
    Jump shift to Blackwood LevelExclusion Blackwood
    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.