These opening bids are from a bidding system used in The Netherlands and was developed by Mr. William van Heusden (aka Willie van Heusden) and Mrs. Arie van Heusden, Mr. Jaap Kokkes, Mr. Kees Kaiser (WBF Code: NED&500602), Mr. Robert (Bob) Kaiser, and co-bridge players. They have been published in the book by Mr. Gerrit Jan R. Forch, (Gerrit Jan R. Förch), with the title Bieden voor Gevorderden, published in the year 1971, ISBN-10: 9060555562 / ISBN-13: 9789023002512


Special Note of Thanks: The photograph of Mr. Arie van Heusden and Mrs. Wilhelmina (Willie) van Heusden is by courtesy of and contributed by Angeline van Heusden, their daughter. Date: April 18, 2012. Angeline van Heusden has benefited the bridge community with her contribution, added to the completion of the history of the game of bridge, and shared with our visitors her gracious donation of this photographic material.

Note: Source for the photograph of Mr. Kees Kaiser.

Opening Bids Only

Note: These bridge players are mainly from Culemborg, The Netherlands, or live close to this village, which is a municipality and a city in the centre of the The Netherlands. This bidding system continues to be played to some extent in this region of The Netherlands. The city is situated just south of the Lek River. The city received city rights in the year 1318.

Bid Strength Meaning
1 : 17+ high card points Shows any shape.
1 : 11-16 high card points Shows various shapes.
1 : 11-16 high card points Shows a 4-card plus Heart suit.
1 : 11-16 high card points Shows a 4-card plus Spade suit.
1 NT: 15-17 high card points Shows a balanced shape.
2 : 11-16 high card points Shows 4+ Clubs and 5+ Diamonds.
2 : 17-20 high card points Distribution: 4-4-4-1; singleton in a Minor suit.
2 : 6-10 high card points Shows a 6-card plus Heart suit.
2 : 6-10 high card points Shows a 6-card plus Spade suit.
2NT: 20-22 high card points Shows 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.

Following 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+ 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, have 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.

Note: The following is an obituary notice for Mr. Jaap Kokkes, printed in Amsterdam, The Netherlands, authored by Mr. Jan van Cleeff. It was published in the year 2005 in the Bulletin, No. 483, Date: April 10, 2005, of The International Bridge Press Association.

Following is an Obituary Notice in the International Bridge Press Association in .pdf file format. The World Bridge Federation code is: WBF Code: NED&500245.

On Thursday, March 24, (2005), Jaap Kokkes passed away at age 81 in his hometown of Amsterdam, following a brief illness. Mr. Jaap Kokkes was one of the dominant forces of post-war bridge in The Netherlands. A mathematics teacher by profession, he celebrated his greatest bridge successes in the sixties and seventies. During that period he collected eight national titles (three teams, four pairs, and one mixed pairs). Kokkes represented his country on numerous occasions at international championships.

He was a member of the Dutch squad that captured the Silver medal at the 1966 European Championship in Warsaw and fourth place at the Deauville Bridge Olympiad in 1968. At the 1990 World Championships in Geneva Mr. Jaap Kokkes won Silver in the Senior Pairs. Mr. Jaap Kokkes was a player with a highly developed sense of ethics as well as a technically gifted player. He was co-developer, together with Mr. and Mrs. Arie van Heusden of Culemborg, Mr. Kees Kaiser, and Mr. Bob Kaiser, of the famous Crazy Diamond system, which has its adherents to this day. Mr. Jaap Kokkes also served in many functions within the Dutch Bridge League and was one of the honorary members of the Nederlandse Bridge Bond.

by Jan van Cleeff

Preserved and archived on this site in .pdf file format for future reference.

Note: Mr. Kees Kaiser and Mr. Bob Kaiser, both of The Netherlands, won Gold at the 1990 World Championship event playing Transnational Teams, conducted in Geneva, Switzerland, with a team composed of players from Israel, Austria, and The Netherlands with players Franz Baratta, Karl Rohan, Moshe Katz, and Nissan Rand. Silver went to Russ Arnold, Billy Eisenberg, Fred Hamilton, Zeke Jabbour, Mike Levine, Thomas Sanders of Team USA1. Bronze went to Howard Hertzberg, Duncan Phillips, Robert Ryder, Bill Solomon of Team USA2.



If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.