Biedermeijer is the official bidding system of the Dutch Bridge Federation, or NBB, De Nederlandse Bridge Bond. When taught to beginners, it is often referred to as Acol, Dutch Acol, Acol2000 or AcolPlus.

This is because Biedermeijer is a trademark of the NBB, so textbook authors cannot call their own variant of the system Biedermeijer. However, it is more similar to SAYC than to Acol. The main characteristics of the system are:

1. 4-card suits are bid up the line, even when opening with 4-4 in the Minor suits.
2. 1 No Trump is 15-17 points.

Biedermeijer convention cards are either Green (options including 4th suit and Jacoby), Blue (options including Splinters and Check-Back Stayman) or Red (options including Lebensohl and Support Doubles). The Biedermeijer Red convention card has an option of 5-card Major opening bids. With that option, which is chosen by most Dutch players (in particular advanced players, but also many club players using the Green or Blue Biedermeijer convention card), it becomes very similar to SAYC. The default opening scheme in Biedermeijer Red is:

• 12-19 high card points, 4 plus Clubs, or 4-3-3-3 with a 4-card Major suit. (Most partnerships open 1 on a doubleton with 4-4 Majors).
• 12-19 high card points, 4 plus Diamonds (officially 3 plus when playing 5-card Major, but few partnerships do that).
• 12-19 high card points, 5 plus Hearts or 4-4 Majors.
• 12-19 high card points, 5 plus Spades.
• 1 NT: 15-17 high card points. Balanced holding (officially, a 5-3-3-2 with a 5-card Major is usually opened with 1 No Trump).
• either 24 plus points and balanced shape (most partnerships invert 2 and 2 with strong balanced hands), or a (semi)-game-force and unbalanced hand with 5 plus Hearts or Spades, or a game-force and unbalanced hand with 5 plus Clubs or Diamonds.
• Either a Weak Two bid in Hearts or Spades.
  or 22-23 high card points and balanced shape (most partnerships: 24 plus high card points).
  or a semi-game-force and unbalanced hand with 6 plus Clubs or Diamonds.
• Muiderberg conventional.
• 2 NT: 20-21 high card points and balanced.

Following are the responses that differ from American styles:

Opener Responder Meaning

• 1 1/1/1 Up the line. Walsh is not very popular in The Netherlands. However, T-Walsh, 1 Negative and Montreal Relay enjoy some popularity.
• 1/1 2 NT Invitational or 15 plus high card points with fit (when invitational may be a 3-card support). There is no consensus as how to proceed after this response.
• 1/1 3 NT No Splinter raise with 12-14 high card points

Jump Shifts Opening strength with a 6-card including at least 2 honours. A Jump Shift by a passed hand is commonly defined as a fit-bid. Bergen Raises enjoy some popularity among advanced players.

Rebids that differ from American styles:

Opener Responder Meaning

• According to the official standard, the opener should show a 5-card Heart suit by rebidding that suit. However, most partnerships do not adhere to that agreement.
• This is a game-force auction.

Reverse jump rebids: With many partnerships, this shows a weak hand with a 6-5 shape.

Freebids that differ from American styles:

Opener Opponent Responder Meaning

• If z is lower-ranking than x, this is a standard forcing free bid (10 plus high card points). However, if z is higher-ranking than x, it shows 8-11 high card points. This means that, after a 1 overcall, a strong hand with Hearts should double. This is still called a Negative Double, but is, in this case, a positive double. Forcing free bids is an option, which is chosen by some Dutch players, especially many advanced players.

Conventions That are Popular in The Netherlands

Multi-Colored 2 Diamonds is either a Weak Two bid in Hearts or Spades or 22-23 high card points and balanced (most partnerships: 24 plus high card points) or a semi-game-force and unbalanced hand with 6 plus Clubs or Diamonds.

The idea is to distinguish between a 5-card Preempt and a 6-card Preempt. Because this is particularly important when partner may have interest in game, some partnerships do not use this convention in 3rd seat. Most do, however.

After an invitational 2 No Trump response, the opener describes his hand:

• Shows Hearts, no maximum. The responder can ask for intermediate strength with 3.
• Shows Spades, maximum. This is to let the strong and unknown hand declare.

The convention is complicated, and many variations exist. So it is not sufficient to agree with partner to play Multi. Even if you agree to play the latest Biedermeijer version of Multi, many details have not been clarified. For example, you should agree whether the 2 response (invitational in case the opener has Hearts) should only be used constructively, and how to proceed. You should agree which doubles on Major suit overcalls can be converted. You should agree how to defend against a double on the 2 opening. You should agree with which strong, unbalanced hands to use the convention, since semi-game-force unbalanced hands with 6 plus Clubs or Diamonds is obviously too vague, and you should agree on how to proceed in that case. You should agree on the meaning of the 3, 3, and 4 responses. Also, notice that the convention is not allowed in many American tournaments. For example, it could not be used at the Salt Lake City Olympic Games. Even when allowed, it will be so by an exception to Brown Sticker Regulations, which means that home-made variants of Multi may not be allowed. Of course, it should not be used against inexperienced players who have no defence against it.

Other Two-Openings

It is very popular to distinguish one’s convention card by means of home-made Two-Openings that can be either weak or strong. Most partnerships protect the 2 opening with a weak variant, typically a Weak Two in Diamonds. But many other Two-Openings are played as well.

Niemeijer

This is an extended version of Puppet Stayman. After a 2 No Trump opening, a fit can (almost) always be found, whether in a Major or a Minor suit. The responses to 2 No Trump are:

Denies a 5-card Major suit and shows interest in opener’s 5- and/or 4-card suit.

Transfer to Hearts. Either a one-suited hand with a mild slam interest, or a very weak hand, or a two-suited hand. Since subsequent 3 / 4 / 4 would be natural and 4 NT would be quantitative, it is not possible to use slam conventions with a one-suited hand after using Jacoby Transfer. Hence, one-suited hands with serious slam interest should be bid with Texas Transfer. The opener should reject with 3 NT with 5 Spades plus 2 Hearts.

Transfer to Spades. As 3. Denies in principle a 4-card Heart suit.

Transfer to Clubs and shows slam interest.

• 3 NT: Shows 5 Spades plus 4 Hearts. Non-forcing, but the opener should show slam interest with 4 (Hearts) or 4 (Spades).
•  Transfer to Diamonds and shows slam interest.
•  Transfer for Hearts (Texas Transfer). Either a hand without slam interest, or a hand with serious slam interest. Subsequent 4 NT is RKC Blackwood.
• Transfer for Spades (Texas Transfer). Either a hand without slam interest, or a hand with serious slam interest. Subsequent 4 NT is RKC Blackwood.
• Promises both Minor suits.
• 4 NT: Shows 5 Spades plus 4 Hearts. Non-forcing.
• 5 : To play.
• 5 NT: Shows 5 Spades plus 4 Hearts and is forcing. The opener should sign off with 6 NT with a minimum and a misfit.

Other Dutch Bidding Systems

Dutch Acol according to Berry Westra

Similar to Biedermeijer but all free bids are forcing. All openings of one in a suit promise a four-card.

Dutch Doubleton

Similar to the 5-card Major variant of Biedemeijer Red, but, as the name suggests, with a 1 opening that on rare occasions can be a doubleton, because 1 promises a 4-card suit. Characteristic of the system is that the 1 response to 1 is either Walsh-like or a 0-6 high card points artificial negative. The opener rebids 1 / 1 on a 3-card suit with a balanced minimum, since 1 NT would show 18-19 high card points. With some partnerships, 1 is forcing and contains some very strong 3-suited hands.

Oranje Klaver – literally Orange Club, but that name is, confusingly, already used for a different bidding system

This bidding system, used by the Dutch National Open Team, is a mixture of Relay-Precision and Dutch Doubleton. Today, as of March 2004, it is still a very young bidding system, under development. The openings include:

• 1 : Either 12-14 high card points and balanced,
  or 18-19 high card point and balanced.
  or 16 plus high card points with 5 plus Clubs
  or shows very strong values with 5 plus Hearts and/or Spades.
• 1 : 11-19 high card points with 5 plus Diamonds or unbalanced with 4 Diamonds.
• 1 : 11-18 high card points with 5 plus Hearts.
• 1 : 11-18 high card points with 5 plus Spades.
• 1 NT: 15-17 high card points and balanced holding.
• 2 : 11-15 high card points or 5 Clubs with 4 Hearts or 4 Spades.
• Saaie Klaver – Literally: Boring Club, all boring hands must be opened with 1.

Similar to Dutch Doubleton, but these openings differ:

• 1 : 12-18 high card points and balanced. Non-forcing with transfer responses.
• 1 : 11-19 high card points with 5 plus Diamonds or unbalanced with 4 Diamonds.
• 1 NT: 12 plus high card points and 5 plus Clubs.

The advantages of this are:

Defending against opponents overcalling the 1 opening, negative free bids can be used safely since the opener must have tolerance for his partner’s suit.

The balanced shape of opener is already known so usually the responder can bid game quickly, knowing that openers hand will not be very slamish. Hence, less information is revealed about opener’s hand, which makes the defence more difficult. This is particularly true because the transfer responses usually cause opener to declare.

Unlike traditional 5-card Major systems, unbalanced hands with length in a Minor can be described immediately, and the responder can support in case of opponent’s overcalls.

The preemptive 1 No Trump opening is used for unbalanced hands, which want to preempt the opponents, rather than balanced hands, which do not want to preempt partner.

Crazy Diamond

These opening bids are from a bidding system used in The Netherlands and was developed by Mr. and Mrs. Arie van Heusden, Mr. Jaap Kokkes, Mr. Kees Kaiser and co-bridge players and has been published in the book by Mr. G.J.R. Forch with the title Bieden voor Gevorderden.

• 1 : 17 plus high card points Any shape
• 1 : 11-16 high card points Various shapes
• 1 : 11-16 high card points 4-card plus Heart suit
• 1 : 11-16 high card points 4-card plus Spade suit
• 1 NT: 15-17 high card points Balanced shape
• 2 : 11-16 high card points 4 plus Clubs and 5 plus Diamonds
• 2 : 17-20 high card points Distribution: 4-4-4-1; singleton in a Minor suit
• 2 : 6-10 high card points 6-card plus Heart suit
• 2 : 6-10 high card points 6-card plus Spade suit
• 2NT: 20-22 high card points Balanced shape

The opening bid of 1 Diamond can show various shapes such as a holding with a maximum of 2 cards in each Major suit, a balanced holding of 12-14 high card points, or a 2-suited holding with one longer suit in the Majors and a second suit in the Minor and a maximum of 3 cards in the second Major suit. The opening bids of 1 Heart or 1 Spade promises a 4-card plus Major suit and a longer-suited Minor suit, which is canapé; either of these bids can also promise a one-suited Major suit, which is designated by the opening, or a distribution of 4-4-4-1 promising a singleton in the unnamed other Major suit.

An opening of 3 Clubs indicates a range of 14-16 points and a good to semi-solid 6-card plus suit, not necessarily the Club suit, whereas an opening of 3 Diamonds shows the same point range with a solid 6-card plus suit, yet to be named. After an opening of 1 Club, the responder attempts to show the number of controls via Step bidding.

Following a 1 Diamond opening, which can show various shapes and which is one-round forcing, if the responder bids a Major, this shows a 3-card plus suit and 0 plus points; a first response of 1 No Trump promises 0-8 high card points and no 3-card Major suit, hence a possible Major-suit distribution of 2-2. These opening bids, as all others opening bidding systems, has undergone revision and modification. Other versions employ the 2 Clubs opening bid to show a range or 11-16 high card points and a distribution of 4-4-4-1 and an opening bid of 2 Diamonds to show a range of 17 plus high card points and a distribution of 4-4-4-1, similar to the Multi 2 Diamond system. Opening 2 of a Major suit indicate weak two-suited holdings.

Lorenzo

The Lorenzo Two is the ultimate Weak Two bid. According to the partnership agreement, it is applicable only when the partnership is not vulnerable. The Lorenzo Two is a mandatory weak bid on the two level. It is a feature of the partnership agreement of the system, which was devised by and is played by Mr. Sjoert Brink and Mr. Erik Oltmans. See: Oltbrink

This system was devised by and is played by Mr. Sjoert Brink and Mr. Erik Oltmans in the Dutch top division. The Lorenzo Two Bids are compulsory and must therefore be made even on hands like xxxx – xxx – xxx – xxx. This system is only in use when not vulnerable.

Opening Meaning

• Pass 8-10 high card points and unbalanced or 9-12 high card points and balanced.
• 1 16 plus high card points, but 17 plus high card points if balanced.
• 1 11-15 high card points, unbalanced, no 4-card suit in either Major suit.
• 1 11-15 high card points and 4-card plus Heart suit.
• 1 11-15 high card points and 4-card plus Spade suit.
• 1 NT 13-16 high card points and balanced shape.
• 2 Lorenzo Two Bid showing 0-7 high card points (8 high card points if balanced) and a 4-card plus Club suit.
• 2 Lorenzo Two Bid showing 0-7 high card points (8 high card points if balanced) and a 4-card plus Diamond suit.
• 2 Lorenzo Two Bid showing 0-7 high card points (8 high card points if balanced) and a 4-card plus Heart suit.
• 2 Lorenzo Two Bid showing 0-7 high card points (8 high card points if balanced) and a 4-card plus Spade suit.
• 2 NT Shows 20-22 high card points and balanced shape.
  Looier

This bidding system is used mainly by beginning players at the Looier Bridge Club of Amsterdam. The philosophy of the system is that certain aspects of bidding theory cause problems when natural systems are taught to beginners:

• The forcing character of rebids and responder’s 2nd bid.
• When to rebid the opening suit if it is a 5-card suit.
• When to rebid the 2nd suit with a 4-4-3-2 pattern.
• The wide range, 12-17 high card points, of a non-reverse 2nd suit rebid.
• Reverse rebids.
• The non-forcing 1 No Trump response even with hands unsuited for a notrump contract.
• Pseudo-natural bids “just to do something forcing”
• Control-showing cuebids
• Recognizing Blackwood apart from the quantitative 4 No Trump.

The openings include:

• 1 in a suit:

either natural, one-suited,
or longest suit when 4-3-3-3 or 5-3-3-2 and 12-15 high card points,
or the highest-ranking of two suits, possibly two four-cards, when minimal (12-15 high card points),
or the lowest-ranking of two suits, possibly two four-cards, when maximal (16-19 high card points).

1 No Trump:

• 16-19 high card points and balanced but not two four-card suits.

The advantage of this system is that the opening and rebid scheme separates balanced hands from unbalanced ones in a very simple way. Also, the rebid immediately separates minimum, or 12-15 high card points from maximum, or 16-19 high card points.

All responses are non-forcing, except for the relays, which is always the cheapest bid in a suit. The advantage of this agreement is two-fold:

With light-invitational hands, or 6-9 high card points, the responder has a choice between a non-forcing descriptive bid and the relay. With stronger hands, he will almost always use the relay. He is never forced by the system to make some strange, pseudo-natural bid.

The forcing character of a bid is very clear. Since the responder is always captain, only relays are forcing.

Also, the slam conventions and the Two-Openings are both bizarre and simple, but it will go to far to describe them here.