Weak two-bids are preemptive bids at the two level, in diamonds, hearts, or spades. (the club suit is reserved for showing a strong game force hand. These weak bids show hands with a good six-card suit and about 5-9 high card points, less than an opening one-bid: ♠ AKJT83 ♥74 ♦876 ♣92. The definition of a “good suit” is a matter of partnership style, vulnerability and position at the table. This hand would qualify as an opening 2♠ bid in most partnerships at any vulnerability in any position.
Most of the strength should be concentrated in the six-card suit, typically with two of the top three honours (AKQ), or three of the top five (AKQJ10). Like preemptive bids at the 3 level or higher, the weak two-bid serves as both an obstructive bid and as a good description of the hand for partner. When vul, you need a suit headed by three of the top five honours. eg: ♠AKJ854 ♠AQ10852 ♠KJ10972. Not vul, your suit could be less robust, eg ♠KJ9854, ♠QJ9852 ♠A109843.
The weak two-bid is made with the intention of interrupting the opponents’ auction but will sometimes make the bidding difficult for partner, who occasionally has a good hand, and your own bidding room has been reduced. Most players avoid opening a weak two-bid with a side four-card major suit or a void.
Responding to a Weak Two-Bid
The weak two bid is primarily a defensive opening, giving responder a good description of opener’s hand. The most popular method of responding is as follows:
• A raise of opener’s suit to any level is to play and could be preemptive. Opener should pass.
• A jump to 3NT or game in a new suit is to play. Opener is expected to pass.
Sometimes responder wants more information and can get it in one of these ways:
• A response in a new suit below game is forcing for one round showing a five-card or longer suit. Opener rebids as follows
1. With three-card support or a doubleton honour, raise responder’s suit
2. With no fit for responder, rebid the original suit with minimum (5-7) and bid a new suit or no trumps with maximum (8-10)
• A response of 2NT is artificial (forcing, with game interest and asking for a further description from opener). Rebid as follows:
1. With a minimum for the weak two-bid, (5-7) rebid the original suit at the three level (2♥ p 2NT p 3♥)
2. With a maximum for the weak two-bid, (8-10), bid another suit to show a feature –usually an ace or king –in that suit. (2♥ p 2NT p 3♣). With no outside feature, bids 3NT to show a maximum. (2♥ p 2NT p 3NT)
Focus on the number of tricks and the number of trumps.
(1) Count the sure tricks, and bid game if enough. A weak two hand will contain about five tricks. A weak three will have six.
(2) If there are not enough tricks for game, bid to the level of the combined trumps. (Law of Total Tricks), e.g.♠ QT643 ♥KT52 ♦9 ♣J86 Partner opens 2♥, and you would bid 4♥. It's not important whether you make it or now. The opponents are able to make a slam in either minor here, and you might keep them out of the auction with the preemptive jump.