Rumble is used against strong artificial forcing strong one club openings. Rumble is the most aggressive in-your-face method you can effectively play against strong one club.
Pass: Not short in either minor, at least 2-2 in the minors vulnerable, at least 3-3 in the minors not vul.
Double: 4+Cs & shortness in Ds, at most a doubleton not vul, at most a singleton vul. No other singleton/void.
1D: 4+Ds & shortness in Cs, at most a doubleton not vul, at most a singleton vul. No other singleton/void.
1H: Both majors, at least 5-3/3-5/4-4 not vul, at least 5-4/4-5/5-5 vul.
1S: 3+Ss & 5+ minor.
1NT: 3+Hs & 5+ minor.
2C: 4+Cs & 5+ in either Ds or Hs, OR 5+Cs & 4+Ds, OR not vul only, weak two suiter, 5+Ds & 5+Hs.
2D: 4+Ds & 5+ in either Hs or Ss OR not vul only, weak two suiter, 5+Hs & 5+Ss.
2H: 5/6Hs, OR, not vul only, weak two suiter, 5+Ss & 5+ in a minor.
2S. 5/6Ss, OR, not vul only, weak two suiter, 5+Cs & 5+Ds.
2NT: Weak with 5+Hs & 5+Cs, OR major/minor two suiter with wild distribution.
Higher suit jumps: Preemptive, long suit, not necessarily weak.
3NT: Both majors or both minors, wild distribution.
4NT: Both minors.
The 1S to 2D canape scheme (shorter suit bid first) forces responder to bid consuming bidding space if bidding the one suit that cannot be held. For examples: 1C-1S-2H (losing bids 1NT, 2C, 2D), and 1C-2D-3C (losing bids 2H, 2S, 2NT). If instead responder bids one of the lower suits it helps the partner of the overcaller to determine what the overcaller has. For example: 1C-1S-2C-?, overcaller likely has 3-4Ss & 5+Ds.
Objective: To force opener to rebid as high as possible – the weakness of artificial forcing openings is that opener has not bid naturally yet – by consuming space it becomes difficult to show complete hand type and strength.
Approach: Bid to the 3 level on an eight card minor fit or nine card major fit. Use pass or correct bids to find right spot while keeping opponents confused as to suits held or not held. The key to Rumble is to use the high frequency of eight card or better minor suit fits when the opponents have their own fit to hinder the opponents in finding their fit and/or appropriate level to play at.
Followup: Overcaller does not bid again, even with distribution, unless constructive or better values held (possible game interest). Bidding again with weak hands seem to help the opponents find their way (since if we have a fit then they have a fit & points).
Over all bids if 1NT or 2NT is available, then the cheapest notrump is artificial and forcing, and is used to ask - it implies some game interest. When the cheapest notrump is available as an ask, all other responses are non-forcing, and game bids are to play.
Over suit bids at 3C or above, new suits are forcing, and 3NT is to play.
After 1C-Pass not vulnerable, showing 3-3 in the minors, the hand in fourth seat (advancer, the partner of the pass) is to jump to 3m with 5 or 6 in the minor, reaching the eight card minor suit as fast as possible. At vulnerable, where pass only promises 2-2 in the minors, advancer can jump to 3m with 6 in the suit. Also after the pass, bids of 2M show 5/6 card suit, but asks partner to pull with a singleton or void. For example 1C-Pass-1D(negative)-2S(5/6Ss, pull if singleton/void in Ss). After 1C-Pass, whether vulnerable or not vulnerable, subsequent bidding is natural, with 1NT as a cuebid if available and 2NT as a jump showing a two suiter of some sort. Over the jump to two notrump bids pass or correct bids are used to find a suit fit. For example 1C-Pass(2-2 if vulnerable)-something-2NT-Pass-3C(can play in Cs so 3+Cs). 2m by advancer over the pass shows 4 in the minor, 5+ in a major, asks partner to pass with four, correct to cheapest suit with two or three in minor e.g. 1C-Pass-any-2C shows 4 in Cs, 5+ in a major.
Over 1C-2NT or 1C-3NT, all suit bids are pass and correct, opener to jump with substantial extra values & distribution.
After bids where the overcaller can have different hand types pass or correct responses are used. These are bids that ask partner to pass if the suit bid is held, or to bid naturally and cheaply if the suit is not held. If a suit bid is doubled, pass says to pass with the suit bid, redouble is SOS with own long suit, asks partner to make the cheapest bid possible. If the opponents double a multiple meaning bid, then new suits are natural and non-forcing, pass asks partner to pass holding that suit, and redouble asks for pass with only just that suit (otherwise make cheapest natural call). If the opponents bid a suit, double says pass if this suit is held, otherwise bid naturally.
After an overcall or double, if partner bids a suit that is not one of the possible suits to be held, it is not pass or correct but simply a natural non-forcing suit bid.
1C-Pass-1D-Double is for the majors, but decent hand held, since partner often not long in either major.
1C-1H(majors)-pass-2H: To play, overcaller will only bid again with constructive values.
1C-1S-pass-2C: Pass with Cs, bid 2D with 5+Ds and 3+Ss.
1C-1S-pass-2D: Pass with Ds, bid 2S with 3+Ss and 5+Cs but bid 2H with same hand & 3Hs.
1C-1NT-pass-2D: Pass with Ds and 3+Hs, bid 2H with 3+Hs & 5+Cs.
1C-Double-pass-3C: 5+Cs, to play here.
1C-Double-Pass-2S: Pass with doubleton or better S, bid 2NT with 4-4 or better in minors, bid 3m with 5 in minor.
1C-1D-Pass-3C: Cs, non-forcing, but more shape then just bidding 2C. 1D shows Ds & C shortness.
1C-2NT-Pass-3S: pass with Ss & a minor but not a lot of extras, bid 3NT with Hs & Cs minimum, bid 4m with Hs & m, wild distribution.
(c) 2001 ETM Information Services Inc. (Canada)