Those who refuse to open the bidding with a four-card major («five-card majorites») have become a big majority in the United States. In other countries (e.g., England) they are a minority. Let’s look at the advantages of each policy, first describing them briefly:
Four-Card Majors
— A four-card major suit may be opened, but only if there is a suitable rebid. For convenience of rebid, a three-card club suit or, rarely, a three-card diamond suit may be opened. In third or fourth seat, when opener can pass a new suit or notrump response, rebid considerations do not apply.
— The bidding may be opened light with distributional hands, but not with balanced hands, using playing tricks as the main criterion. At least two defensive tricks are required. A 12 HCP balanced hand may be opened if honors are working together ( 
965 
AK43 
75 
KQ52) but not if they are scattered ( K65 A943 K5 Q752), recognizing that honors in combination are worth more than isolated honors. Lead direction is an important consideration.
— A 1NT rebid shows 13-15 HCP, leading to a 16-18 HCP range for opening 1NT, 19-20 HCP for a jump rebid of 2NT, and 21-22 HCP for opening 2NT.
— Bidding very weak four-card suits is avoided by both opener and responder. Raises with good three-card support (J10x or better) are therefore acceptable. With a singleton or void even three small cards are good enough in a pinch.
— One-over-one responses are not necessarily «up the line.» Responder can skip over a very weak suit when the hand calls for a better bid. Conversely, good diamonds are bid in preference to a weak major when responding to 1.
— Reverses by opener are not forcing after a one-over-one response if responder’s suit is four long, but are
forcing after a two-over-one response. In any case, opener may pass if responder makes a discouraging rebid, but may not pass responder’s rebid of his suit (which he must rebid with more than four, as a first priority).
— Reverses by responder are forcing, but not forcing to game. Again, if opener makes a discouraging rebid, responder may pass.
— Two-over-one responses do not promise another bid. With a shaded response, responder may pass on the next round if opener does not make a strength-showing rebid.
— After a two-over-one response, opener’s rebid of 2NT or raise of a minor suit implies extra strength (but a heart raise does not). Bidding a new suit at the three level is not only forcing, but promises another bid if responder doesn’t bid game..
The general philosophy is one of bidding real suits, with a minimum of forcing sequences.
Five-Card Majors
— A major suit opening promises five or more cards in the suit, and a 1NT response is forcing. After a 1NT
response, opener may rebid his suit only if it is at least six long, so with 5-3-3-2 shape he must bid a
three-card minor if he can’t raise notrump. Many players use…Click here to continue reading