A takeout double typically shows a hand with opening bid strength and support (at least 3) for each of the unbid suits OR a hand too strong for an overcall (approximately 18+ HCP). Some players make a takeout double over a minor opening with 4 in each major, gambling that partner will bid one of them. Typically the doubler has shortness in the opponents' bid suit.
(a) a minimum bid of a new suit shows a weak hand (9 or fewer ponts). Responder has simply bid the longest unbid suit.
(b) one notrump shows 6-9 and a stopper in the opponents' suit.
(c) a single jump in a new suit shows 10-12 points and is game invitational but is not forcing.
(d) a double jump shows a weak hand (10 or fewer HCP), but t least 6 in the suit. This basically is a preemptive bid.
(e) 2NT show 10-12, and stopper, and is game invitational
(f) shows 13-16 HCP, or slightly fewer points with a very good and long suit.
(g) Cue bid typically shows 13+ HCP without a stopper, but often is made with 10-12 and four cards in each major.
Responses in Competition
There are several different response structures in competition. Some play that partner should always bid over opponents' redouble. Typically, however, partner is relieved of the obligation to bid if opponents bid again before partner's turn to bid.
(a) Over a redouble, partner
(1) passes without a clearcut suit, or
(2) makes a bid showing the best suit. This does NOT promise any strength.
(b) Over an suit bid, partner
(1) bid a new suit to show 6-9 points
(2) double for penalty (most partnerships play negative/responsive doubles in this situation)
(3) jump to show a hand with 10+ HCP
Rebids by Doubler. Where partner has shown a minimum,
(a) pass with 15 HCP or fewer.
(b) Single raise at the 2 level to show 16-18 HCP (e.g., 1H DBL pass 1S pass 2S!)
(c) Single raise at the 3 level to show 18-20 HCP (e.g., 1H DBL pass 2C pass 3C!)
(d) Jump raise to the 3 level shows 19-20
(e) Bid a new suit to show 18-20
(f) Jump in a new suit shows a strong hand (16+) and 6 cards in the suit
(g) Notrump hands show very strong hands.
(1) 1nt shows 18-20
(2) jump to 2nt shows 21-22
(3) non-jump to 2nt shows good 18 to 20)
(4) cue bid of original suit shows 21+ . Although one-round forcing, doubler is not required to bid again. Responder should jump bid to show maximum.
Where partner has jumped, doubler may pass or make any other bid to force to game
Where partner has cue-bid, partner makes a natural bid, showing preference for a 4+ card major
Where partner has bid one notrump, double may bid 2nt to invite, signoff in game of 3NT or another suit, cue bid the enemy suit to show a very strong hand, or pass
Other instances of takeout. Where partner has not bid or doubled, the double of a natural suit is takeout. Most partnerships agree at which point the double is for penalty vs. takeout, with 4D being the most common. Here are some typical takeout double situations:
(a) Over opponents' weak preemptive opening. The higher the level of preempt, the better the takeout double's hand should be in value and shape.
(b) Double after a suit response to any opening bid is takeoug and STRONGLY implies 4 cards in both unbid majors.
(c) Balancing Doubles through 4D. The Doubler does not need opening values to make this bid. Again, partnerships have different agreements when the double is no longer takeout, but penalty.
(d) Double of a one or two notrump response of opponent's opening bid. Although this is takeout by default, many partnerships play a double in this position as penalty.
(e) Doubles by a passed hand are still takeout, but showing greater shape to compensate for the lack of opening values.
(f) After making a simple overcall or after having already made a takeout double, the double is again for takeout, but this time shows a strong hand typicall of a maximum overcall.
(e.g., 1S 2C pass pass 2S DBL! showing a maximum hand and support for unbid suits).