Muiderberg: The Dutch Two

The Muiderberg opening is one of the weapons of Dutch bidding. It shows exactly 5 cards in the bid suit, and 4 cards or more in a minor. Because of the 5-4 distribution, the probability for an 8-card fit is the same as for a weak two: approximately 75%

Although mostly played as a weak opening (approximately 6-10 HCP), some pairs play it with opening strength (11-15 HCP) to resolve bidding problems elsewhere. In Magic the bid is weak but constructive (8-11 HCP). With a 5-5 you can be more agressive, regardless of the agreed strength.

2: Weak, 5 + 4+ /
2: Weak, 5 + 4+ /

There are two response schemes to the Muiderberg. First the easiest one. The more complicated responses can be found below.

Response to 2M

Further Bidding
2NT Asking bid, possibly weak with both minors Opener rebids his minor, also see below
New Suit 6-card suit, forcing
3M Pre-emptive
3NT/4M To play

2M - 2NT - 3m - ?

  • 3M is invitational to game
  • 4m is slam interest for the minor
  • A new suit is a control bid for the major

    More complicated responses

    Response to 2M

    Further Bidding
    2 (over 2): Constructive but NF Opener shows his minor, raises, or passes
    2NT Strong Relay, asks strength and minor See Below
    3 Weak with both minors Opener passes or bids 3
    3 Invite to 4 in the major
    3 (over 2): Natural and forcing
    3M Pre-emptive
    3NT/4M To play

    2M - 2NT - ?
    3 Minimum with
    3 Minimum with
    3 Maximum with
    3 Maximum with
    4 6-card
    4 6-card