FOUR-SUIT TRANSFERS. Transfer bids into all four suits have achieved great popularity in tournament play since the Eighties. The usual plan, in response to 1NT, is:
2♦ shows heart length
2♥ shows spade length
2♠ shows club length
2NT shows diamond length
This method was favored by one-third of the respondents in Bridge World Standard 1994 and 47% in Bridge World Standard 2001. Far less popular was the alternative in which 2NT shows clubs and 3♣ shows diamonds. After 2♠ and 2NT, the opener should accept the transfer if he has a fit with responder’s suit and make the intermediate bid if he does not (some partnerships reverse this procedure). If responder has a good minor suit, perhaps six to the A-Q, he can play 3NT with a fit and three of his suit without one. If responder has a weak minor two-suiter he can bid 2NT and pass the rebid. The responder will often have a strong hand and continue bidding. The meaning of a subsequent major-suit bid needs agreement, the simple options being to use bids of the major either as natural or as shortage, the latter being more common. With length, responder will probably use Stayman. Using this method, a direct 2NT bid by responder is not available as a natural invitation. To give such a message, the responder must use Stayman and follow with 2NT, which does not, therefore, imply possession of a four-card major suit. Related: Minor-Suit Stayman. Other schemes are possible: (1) 2♠ shows clubs, 2NT is natural, 3♣ shows diamonds; (2) 2♠ shows minors, 2NT shows clubs, 3♣ shows diamonds.
SOURCE: "Conventions", The Official ACBL Encyclopedia of Bridge, 7th ed. Horn Lake: American Contract Bridge League, Inc., 2011, page 286. Print