The fundamental goal of any successful Doppelkopf player is to get the most from his/her cards. A part of this is for the partners to reach the optimal bid level. This is where the Essener System can be particularly helpful by providing confidence in announcements (or counter announcements). It does this by providing a better understanding of the structure of a hand so that bids can be during the first three tricks when much information is still missing.
Following are the fundamental principles:
Information about the contents of a player's hand should be revealed only when it improves the chances of the partnership.
This is generally the case when one holds an above-average hand and/or one has already taken the initiative in the game.
Information requested by a partner must be provided.
There is only one exception: One has information about the hand that it would Man besitzt weitere Informationen über das Spiel, die der Partner bei seinen Überlegungen unmöglich hat mit einbeziehen können. Das Essener System verwendet zur Informationsübermittlung die folgenden, selbstverständlich regelkonformen Hilfsmittel (zumeist Kombinationen):
The individual components have the following main meanings:
Announcements are only used in the Essener System when they increase the anticipated value of the game. The anticipated value is determined by multiplying the probability of the various options by the value of each game, if won. This means that one must consider the effect of the announcement on the play that follows. The following table shows on a purely mathematical basis how certain one must be in order to make certain announcements.
Tab. 1: Required Certainties for (Counter-)Announcements
The items in the table are out of 100% assuming a positive response by the partner.
2) Selecting the timing of announcements:
The following is the basic rule:
Announcements made prior to the last possible moment provide additional information.
This additional information is provided by the timing of the announcement in relation to the game situation. The following are examples:
1) Announcements when playing a card or when another player plays a card.
This indicates particular strength and can signal also the possession or lack of particular cards. The exceptions are announcements made in response to warning signs in conventional situations. When made in response the usual indication is the possession or absence of a card or suit. Otherwise, both interpretations are possible.
2) Announcements before playing a card.
Usually made when the partners have not yet been determined in order to clarify the situation. Otherwise, the goal is to indicate something other than a "normal" game. A "normal" game is one which is optimal without additional announcements.
3) Delay in leading or playing a card (simulated reflection)
This is always a request of your partner for additional information. The information sought can be of various types: Are you my partner?; Partner, take this trick; Partner, do you have a particular card; etc.. The partner should answer according to the conventions given above. Players should exercise a great deal of self discipline and should consider the play that has been made so far and the basic probabilities.
4. Conventional plays
We mean here plays (up until the last moment) that in combination with items 1-3 always provide the same information. They require a particular response from the partner. In order to be a meaningful convention, several requirements must be met:
The following chapters explain in more detail the general principles given here. They are organized by the type of game: normal, Marriage, Solo, etc.. In each case, we will seek to provide useful examples of how the system can be used. Remember, however, that these are simply guidelines and cannot cover every situation. Part of the fun is learning the exceptions to the rules!