by Bill Treble, Winnipeg, Man.

Nowadays, a number of topflight partnerships play a "multi" two-diamond opening, showing a weak two-bid in one major or the other. Many defenses to this opening have been suggested, but none seems to have gained universal acceptance. An effective defense should exploit the fact that, while the opponents don't know what opener's major is, neither does his partner. My suggestion:

Directly over the opening two-diamond, suit overcalls are natural. Jump overcalls are intermediate, promising a long, strong suit with opening-bid values or slightly better. Two notrump shows 16-18 in a
balanced hand, usually no four-card major. Three notrump is to play, and may be semi-gambling.

The direct double is strong takeout of one major or the other, 16+ HCP.
For example, 
(a), S- KJTx H- x D- AQJx C- KQxx
(b), S- xx H- AKJx D- KJx C- AJxx

Doubler, at his next turn, shows which major he is taking out. After,
  2D      Double    2H     Pass
Pass         ?

doubler would bid two spades with (a). This cannot be great spade length, since he would have overcalled. Therefore, this shows takeout of hearts. With (b), opener could double again to show takeout of spades, i.e., a desire to penalize two hearts. If doubler's partner had a good heart holding, he would have doubled two hearts - he knows he is facing a strong hand because of the initial double.

With takeout hands too weak for the direct double, such as, 
(c), S- KJxx H- x D- AQxxx C- KTx
(d), S- xx H- AJ9x D- KQx C- Axxx
you must pass the two-diamond opening. The, after,

   2D     Pass      2H      Pass
Pass        ?

you bid two spades with (c), to show a minimum takeout of hearts. You can double with (d), to show a minimum takeout of spades. Partner, knowing you have fewer values than if you had doubled directly, will be well placed to select the final contract.

The opponents might make the auction awkward fot you if responder preempts in a major (he has to have both to do this).

   2D    Double    4H        ?

Here, a double by advancer (doubler's partner) is takeout-oriented, with some values, enabling the original doubler to pass if he has the opponent's suit. If advancer passes, doubler's repeated double is for