A Penalty Double should be used if your opponents contract is likely to fail. A successful double increases the penalty and can be a effective route to good scoring. A Double can be used where you have a good holding of trumps, your opponents have overbid their strength or you have a long suit against a NT contract. Where your opponents have bid at the 5 level, against your bidding, using a Double should always be considered.
Doubling low level contracts is risky. Getting 7 or 8 tricks is often not difficult. For this reason the double is used for other purposes on bids less than 3C.
RULE OF 19
When 1NT is doubled, the double is always for penalty and shows 16 plus points. The Responder must judge whether the contract will succeed. The Responder adds her points to 12. If the total is less than 19 the contract is likely to fail and the responder bids her longest suit. The opener must not rebid.
For the doubler’s partner the same logic applies. For the double to be safe, 21 points are required. Adding your points to 16 determines whether evasive action is required. If it is, bid your longest suit.
When opposition have opened, you can find an overcall difficult to find even though you may have the strength. By using the Takeout Double you are showing an opening hand with at least 3 cards in each of the unbid suits. A Takeout Double obliges your partner to bid her longest suit irrespective of her hand’s strength. This bid is not mandatory if the opponents make an intervening bid.
After an intervention a response to the takeout double can still be made by a free bid. This shows a hand of sufficient strength and/or length to be worthwhile.
If your partner responds to your Takeout Double by bidding Openers suit (a Cue Bid), he is asking you to further describe your hand. He is saying, “we have game but I don’t have a five card suit and I don’t have stoppers“. So bid NT if you have stoppers or tell him your best Major.
NB When an opening bid in a suit is doubled it is never for penalty and obliges partner to bid.
When your partner has opened and your opponents have overcalled, it is often difficult to respond because of no five card suit and insufficient strength to bid at the 2 level. The negative double shows 4 cards in the major suit not bid by the opposition i.e. 4 spades if hearts bid by overcaller or 4 hearts if spades bid by overcaller.
The opener must bid again unless there is an intervention.
When your opponents are using an artificial bid such as Red Suit Transfers, Stayman, Gerber, Blackwood Responses, Relays, 2C Openings, Control Showing Cue Bids etc., a Double can be used to ask for a lead in the bid suit. This is when the artificial bid does not indicate strength in the bid suit.
If the Lead Directing Double (LDD) is at a low level say after 2C Stayman then it shows some strength and length in Clubs - an overcalling hand.
LD doubles tend to be overused. Think about who is likely to be on lead - you or your partner?
At a high level such as: 1NT - P - 4C (Gerber) - X then a LDD shows AK of Clubs or just A of Clubs Or Void in Clubs.
You do not need to alert a Lead Directing Double.
1NT - PASS - 2D(transfer) - X (Lead me a diamond).
In this example, the double will not be left in by the Opener because Responder has shown hearts and Opposition have shown diamonds.
If you have already Overcalled showing at least 5 of a suit and then Opps bid your suit (Cue Bid say), A LDD from you now shows extra strength or length in your suit - such as 6 Cards.
1C - 1S - PASS - 2C (UCB showing support for spades and 10+ HCP) - X (LDD showing 6 Clubs).