Conventional Wisdom

Over Opponent’s Takeout Double:

Many pairs agree to change the meanings of certain bids by responder if an opponent makes a takeout double. You should discuss with your partner what effect (if any) an opponent’s takeout double has in a typical auction.

New Suit Forcing:

When responder makes a “one-over-one” response in an auction where he opponents are silent, e.g.,

Partner RHO You LHO
1♣ Pass 1 Pass

opener is required to bid again. This concept is a cornerstone of contract bridge bidding, and it is so fundamental that the overwhelming majority of players extend this idea even to auctions in which the opponents make a takeout double. Therefore, in the auction

Partner RHO You LHO
1♣ Dbl 1 Pass

most play that opener must make a rebid. Another way to put it would be this: over an opponent’s takeout double, a one-level response is forcing. If your partnership has this agreement, check the “1 level” box. A two-over-one response, however, is different. For example, in the sequence

Partner RHO You LHO
1♠ Pass 2♣

most play that 2♣ shows invitational or better values. Change the auction slightly to this,

Partner RHO You LHO
1♠ Dbl 2♣

and you may be one of the many pairs who have agreed to define 2.Y. as non­forcing – opener may pass. Responder’s hand could be something such as
♠9   8 7 3   10 5 4   ♣K Q J 7 6 2.
The reason for this difference is right-hand opponent’s takeout double, typically promising opening values and support for the other suits. Since the chance of your side reaching game is diminished, many pairs believe that it makes more sense to define some of responder’s actions as weaker than they would be in a non-competitive setting.

Jump Shift: Without interference, your partnership may agree to play jump shifts (e.g., 1♣ by partner – 2 by you) in any number of ways: very strong, intermediate or weak.
When the opponents intervene with a takeout double, however, many partnerships alter the meanings of their jump shifts. The popular choice is to treat a jump shift after a takeout double as weak. The reason for this is practical: if partner has an opening hand and RHO has an opening hand, it’s almost impossible for responder to have a hand that’s good enough to qualify for a strong jump shift. It’s much more common for responder to have a weak hand with a long suit, making the weak jump shift a more useful option.
Therefore, in an auction such as

Partner RHO You LHO
1 Dbl 2♠

your partnership should decide whether 2♠ is forcing, invitational or weak and check the appropriate box.

Redouble implies no fit: In an auction that begins

Partner RHO You LHO
1X Dbl Redbl

the redouble typically announces that your side has the balance of power. It usually promises at least 1 O high-card points, and it invites partner to penalize the opponents if they run to one his long suits.
There are exceptions worth discussing, however. One of the most important ones is when responder has a fit for opener’s suit, especially a major. For example, if partner opens 1♠ and RHO doubles, what do you call, holding
♠Q J 3 2   A 7   9 8 3   ♣K J 8 6?
You have 11 HCP, but although you have the strength to redouble, it’s better to tell partner about the spade fit. (See next month’s column for how to handle this type of hand.) Many pairs also avoid redoubling when responder has a good suit of his own. For example, in the auction

Partner RHO You LHO
1♣ Dbl ?

if you held
♠8   A K Q 8 6   K 5 4 3   ♣9 5 4
it’s better to bid 1 than to redouble, since the LHO may preempt in spades. It’s better to get your suit in now. That means that many experienced players will reserve redouble for hands which lack a fit for partner’s suit and lack a good suit of its own. If redouble implies no fit, check the box.