In the game of bridge Ekren refers to a preemptive opening of 2♦ defined as 4-4, 4-5, 5-4 or 5-5 in the majors and 3-10 hcp. This conventional preempt was designed by Bjørn Olav Ekren from Norway. It can be seen as an example of the modern style of ultra aggressive preemptive bidding.
Responses to a 2♦ Ekren opening :
- Pass =: To play (can be a tactical manoeuvre in the absence of a major suit fit and does not guarantee long diamonds)
- 2♥/♠ : To play
- 2NT : Relay (invitational or stronger)
- 3♣ : Natural, not forcing
- 3♦ : Invitational with 3-3 in the majors
- 3♥/♠ : Preemptive, to play
- 4♥/♠ : To play
In responding to the 2NT relay the opener indicates whether (s)he holds a minimum or a maximum (because of their playing strength 5-5's are generally considered maximum), and - in case of a maximum - the distribution in the majors:
- 3♣ : any minimum (responder's 3♥/♠ rebid now indicates an invite)
- 3♦ : 5-5 min or max (creates game force)
- 3♥ : 4-5 max (creates game force)
- 3♠ : 5-4 max (creates game force)
- 3NT : 4-4 max (creates game force)
Variants of Ekren include the use of the 2♥ opening to indicate a weak hand with at least a 4-4 in the majors. This treatment has the advantage that the left hand opponent of the opener can hardly gamble on the fact that (s)he will get a second chance to bid.
Another variant that is popular in the Netherlands (where it is referred to as ''Tilburg Two'') and Belgium is to accommodate the Ekren hands as a weak variant in the strong 2♣ opening. This leaves untouched the 2♦/♥/♠ openings which are commonly utilised in the Low countries as Multi 2 diamonds and Muiderberg openings. Also, a 2♦ relay is now available to responder that can be used to ask for the longest (or better) of the two major suits.