Weak two bid

A prototype of the weak two was used in auction bridge, and the principle was attested as early as 1910 by J.B. Elwell.[3] It was incorporated into the Vanderbilt Club system. In early 1940s, Howard Schenken developed the modern weak two-bid along lines similar to Vanderbilt's.[1]

In Charles Goren's original bidding system, when a player opened the bidding with two of a suit, this signified that the player held a very strong hand. (This later became known as the strong two bid.) Later players found it more effective to reserve only the conventional two clubs opening; to show a strong hand. That left the room for opening bids of 2♦, 2♥, or 2♠ to show a weak hand with a six-card suit. This became known as the weak two bid. In some systems, a bid of 2♣ shows a strong hand with a five-card suit, and a bid of 2♦ shows a hand that is similarly strong, but balanced. These alternate versions are less common.

Standard American and Standard English Acol responses to weak twos are as follows...

• A raise of the bid suit extends the preempt, and is to play. The weak two bidder does not bid again.
• A bid of 2NT is 17+ artificial forcing enquiry.
• A new suit is forcing and at least invitational.

This is known as RONF for raise only non-forcing bid.

After a 2NT enquiry.

• A bid of three of any suit other than the suit of the "weak two" bid shows a "feature" (typically either an ace or a king) in the named suit and maximum.
• A bid of three of the suit of the "weak two" bid denies a "feature" in any other suit and is minimum.
• A bid of 3NT shows a maximum without a feature.

Some pairs play a feature shows a stop for NT.

Weak Pulls

• A new suit at the lowest level shows a weak hand with a long suit and is to play. The weak-two bidder does not bid again.

Ogust

• When using the Ogust convention, the following alertable responses apply:
  • 3♣ shows a "minimum" hand and a "poor" suit.
  • 3♦ shows a "minimum" hand and a "good" suit.
  • 3♥ shows a "maximum" hand and a "poor" suit.
  • 3♠ shows a "maximum" hand and a "good" suit.
  • 3NT shows A-K-Q of the preempt suit.
    Here, the definitions of "minimum" and "maximum" hands and "poor" and "good" suits are matters of partnership agreement.
  • A range of seven HCP or less for a "minimum" hand and eight HCP or more for a "maximum" hand is fairly typical.
  • Since "strict" preempts usually show either K-Q or better or Q-J-10 or better, partners who play "strict" preempts typically regard a "good" suit as something more (K-Q-J or better, for example). On the other hand, partners who are less strict in their preempts might define a "good" suit to have either K-Q or better or Q-J-10 or better and a "poor" suit to have anything less.
    There are several variations on the Ogust convention. Ogust's original definition, for example, had the swapped responses in the red suits and did not include the 3NT response. The responses shown here, however, are now pretty much standard.

Playing Parallel Twos an opening 2♣ shows five hearts 7-11 HCP, 2♦ shows five spades 7-11 HCP. The 2♣ and 2♦ opener's are referred to as Parallel Twos because they are played in parallel with the regular six card weak twos in hearts and spades. You can play them in any bidding system Acol, SAYC, Precision, Blue Club etc. See the eBook "Parallel Twos For You" N.Jones June 2014.

The Muiderberg convention, like Parallel Twos, allows weak two-level bids to be made on five card suits, but use different bids and have additional shape constraints to allow use on weaker hands. Typically a non-vulnerable Muiderberg Two shows 5-9 points, a 5 card major and 4+ cards in a minor, and the bid is 2 of the major. Vulnerable, a 5-5 shape is often preferred. To find opener's second suit, responder can bid 2NT (strong enquiry) or 3♣ (weak, asking opener to pass or correct to 3♦). The regular six card weak twos in hearts and spades are generally shown using the multi 2 diamonds.

Antispades Twos (also known as Antispades Weak Twos) make up a two-level opening based on either a six-card suit or a two-suiter with at least nine cards distributed across any two suits. The 2♣ opening promises 5-10 HCP and either a 6-card club suit, or clubs and diamonds, or clubs and spades. The 2♦ opening promises 5-10 HCP and either a 6-card diamond suit, or diamonds and hearts, or diamonds and spades. The 2♥ opening promises 5-10 HCP and either a 6-card heart suit, or hearts and spades, or hearts and clubs. (The 2♠ opening is artificial and very strong, promising either 23+ HCP balanced, or a hand of 16+ HCP with four losers or fewer.)

Partnerships can adopt Weak, Parallel, Lucas or Antispades Twos and retain their existing one-level bidding structure — for example, Acol or Five-card Majors — along with a strong balanced meaning for the 2NT opening.

• Preempt
• Strong two bid
• Antispades Twos
• Multi two diamonds