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 (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, 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
minor suit 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 bid with a single-suited major. These hands may instead be bid using the
Multi 2 diamonds 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.
See also
*
Antispades Twos
References
Bibliography
*
{{WPCBIndex
Bridge conventions