Conventions in depth
When an opponent opens, your double asks partner to choose one of the other suits. The higher their bid, the more strength the double shows.
A takeout double says: “I have opening values and I can play in any suit you choose except theirs.” The classic shape is short in their suit (two cards or fewer) with three or more cards in every other suit. Partner must answer, even with nothing, because the double asks a question.
In BidMaestro, points for a takeout double are high-card points plus length points (one for each card over four in a suit).
The higher the opponents open, the higher partner has to answer, often with a weak hand. So the double needs more strength as the level rises. In the pass-out seat, after their bid has been passed round to you, you can double with about 3 points fewer: partner’s pass did not deny values, and someone has to protect them.
Some hands are too strong for a simple overcall or a 1NT overcall but do not have takeout shape. They start with a double anyway and show their real hand at the next turn, by bidding their own suit or notrump.
So partner treats the double as takeout until the doubler bids again. A new suit or notrump from the doubler at the next turn shows this stronger hand.
After a one-level opening, the partner of the doubler (the “advancer”) shows strength by the level of the answer:
When partner doubled in the pass-out seat, these ranges move up by about 3, because the doubler may be up to 3 points lighter. There the cue-bid is not used: with a strong hand, jump or bid game instead. Over a double of a three-level pre-empt, a jump to the four level shows the same 9 to 11, counting shortness and extra trumps when the suit is a five-card major.
If the doubler then raises your answer one level, that shows a strong double (17 or more high-card points and 17 or 18 counting the fit) and invites game. In a major, bid game with 7 or more points counting shortness and extra trumps; otherwise pass. Pass a raise of a minor: five of a minor needs eleven tricks, more than the invitation is built for.
A player who has already bid, or whose partner has, can also double the opponents’ suit to show a strong hand: 17 or more points counting a point for each card over four in a long suit, and at most three cards in their suit. With four or more of their suit, pass instead. Partner answers this double the same way as a takeout double. The doubler then bids again: game in partner’s suit with four-card support and 19 or more points counting shortness, a strong five-card suit of its own, or 3NT with their suit stopped and 20 or more points.
If the doubler’s left-hand opponent bids or raises, you no longer have to answer: you may pass with a weak hand. A free bid of a new suit at the cheapest level shows 6 to 8 points, counting a point for each card over four in a long suit, and four or more cards in the suit. Stronger hands use the same steps as without the bid: a jump with 9 to 11, game in a five-card major with 12 or more points counting shortness, otherwise a bid of the opener’s suit with 12 or more. After their raise, if you play Responsive Doubles, a double with two four-card unbid suits and 8 or more high-card points (at the two level) asks partner to choose a suit.
The rule of thumb: the higher their bid, the more you need to double, because partner may have to answer at that level with nothing. Remember the steps: about 12 over a one-level bid, 15 to 16 over a weak two, and 17 over a three-level pre-empt.
