Muiderberg convention
Encyclopedia
The Muiderberg convention in the card game bridge
is also known as the Dutch Two opening. It is a two-level preemptive opening based on a two-suiter with precisely a five-card major
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 named after the Dutch village Muiderberg, the residence of the designers of this two-level opening (Onno Janssens and Willem Boegem).
The 2NT response is often defined as forcing to game, for example in Biedermeijer and AcolPlus. In particular, with a strong hand with an own 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:
Both approaches 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.
Contract bridge
Contract bridge, usually known simply as bridge, is a trick-taking card game using a standard deck of 52 playing cards played by four players in two competing partnerships with partners sitting opposite each other around a small table...
is also known as the Dutch Two opening. It is a two-level preemptive opening based on a two-suiter with precisely a five-card major
Major suit
In the card game contract bridge, the major suits are spades and hearts . The major suits are of prime importance for tactics and scoring as they outrank the minor suits while bidding and also outscore them...
and a minor suit
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 than contracts made in the major suits , and they rank lower in bidding. In particular, one can make game with a bid of 4 in a major suit, while a bid of 5 is...
(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 named after the Dutch village Muiderberg, the residence of the designers of this two-level opening (Onno Janssens and Willem Boegem).
System
The partner of the Muiderberg opener can take the following actions:- pass (with tolerance for the opened suit)
- bid 3 (a pass-or-correct bidPass-or-correct bidIn the card game bridge a pass-or-correct bid , is a non-forcing bid that asks partner to pass or bid differently based on her/his holding...
) - 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 suitMinor suitIn contract bridge the minor suits are diamonds and clubs . They are given that name because contracts made in those suits score less than contracts made in the major suits , and they rank lower in bidding. In particular, one can make game with a bid of 4 in a major suit, while a bid of 5 is...
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 an own 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 a four clubs
- bid 3 with a minimum and diamonds / with a four diamonds
- bid 3 with a maximum and clubs / with a five or more clubs
- bid 3 with a maximum and diamonds / with a five or more diamonds
- bid 3NT with 4-4 in both minors
- bid 4/ with a 6+ cards in the bid suit
Both approaches 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.