Muiderberg is a bidding convention in the card game

bridge A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somethi ...

. It is a two-level preemptive opening based on a two-suiter with precisely a five-card

major Major (commandant in certain jurisdictions) is a military rank of commissioned officer status, with corresponding ranks existing in many military forces throughout the world. When used unhyphenated and in conjunction with no other indicators ...

and a

minor suit In contract bridge the minor suits are diamonds () and clubs (). They are given that name because contracts made in those suits score less (20 per contracted trick) than contracts made in the major suits (30 per contracted trick), and they rank low ...

(four-card or longer). In Muiderberg the 2 opening denotes five hearts and an unknown minor suit, whilst 2 denotes five spades and an unknown minor suit. The convention is also known as the Dutch Two, Lucas Two or Woo Two (mainly UK) opening. __NOTOC__ The convention is named after the Dutch village

Muiderberg Muiderberg () is a village in the municipality of Gooise Meren in the Netherlands. It lies about 6 km north of Bussum and 2 km west of Naarden, adjacent to the Naarderbos. Geography Muiderberg is in the east of the municipality of ...

, the residence of the designers of the convention – Onno Janssens and Willem Boegem.

Responses

The partner of the Muiderberg opener can take the following actions: * pass (with tolerance for the opened suit) * bid 3 (a

pass-or-correct bid In the card game bridge a pass-or-correct bid (or convertible bid), is a non-forcing bid that asks partner to pass or bid differently based on her/his holding. Pass-or-correct bids are generally used as responses to multiway bids. A typical example ...

) * bid 3 to invite for game in the major suit * bid 2 (over 2) as a contract improvement (opener is allowed to raise with a suitable hand) * bid 3/ (opener's suit) as a preemptive raise * bid 3/ (other major) which is non-forcing but invitational * ask for the

using a 2NT relay bid with a strong hand. The 2NT response is often defined as forcing to game, for example in Biedermeijer and AcolPlus. In particular, with a strong hand with a good suit of its own or with support for partner's opened suit, responder must bid 2NT first, as there is no other way to establish a force. The Muiderberg opener can respond in several ways to the 2NT answer: * bid 3 with a minimum and clubs / with four clubs * bid 3 with a minimum and diamonds / with four diamonds * bid 3 with a maximum and clubs / with five or more clubs * bid 3 with a maximum and diamonds / with five or more diamonds * bid 3NT with 4-4 in both minors * bid 4/ with a 6+ cards in the bid suit Both approaches (2NT forcing to game or forcing for one round only) are equally popular. In competition, 3 is natural (opener is expected to pass) while 2NT asks for opener's minor suit and is not necessarily strong. Further, 4/ are defined as fit-bids in competition.

Variants

Partnerships may choose to play Muiderberg Twos (or the variants below) as: (a) at least 5-4 shape, (b) at least 5-5 shape, or (c) at least 5-4 when non-vulnerable but at least 5-5 when vulnerable, for added safety. Statistically, 5-4 hands are about four times as common as 5-5. A variant known as Lucas Twos allow for five cards or more in the bid suit (diamonds, hearts or spades) and four cards or more in a second suit which can be any of the remaining three suits. Particularly in the UK, the term Lucas Two is often used to describe what is actually a Muiderberg Two, where the second suit has to be a minor; this makes it safer for responder to explore for a second-suit fit if short in opener's longest suit. A difficulty with Muiderberg and Lucas Twos is that it is no longer possible to make a

Weak Two The weak two bid is a common used in the game of contract bridge, where an opening bid of two diamonds, hearts or spades signifies a weak hand, typically containing a long suit. It may be deployed within any system structure that offers a forcing ...

bid with a single-suited major. These hands may instead be bid using the

Multi 2 diamonds Multi-coloured 2 diamonds, is a contract bridge bridge convention, convention whereby the opening bid of 2D shows a defined range of hand types. These always include a Weak two bid, weak-two bid in a major suit, and the second option, that must be ...

convention. Another variant, called Antispades Twos, provides for either a two-suited hand containing at least nine cards in the two suits with four or more cards in the bid suit — clubs, diamonds or hearts — and four or more in another suit, or a single-suited hand of at least six cards in the bid suit, in a hand worth 5–10 HCP.

References

Bibliography

* {{WPCBIndex Bridge conventions

Responses

Variants

See also

References

Bibliography