Exclusion Blackwood.

A question about aces (excluding the ace in the color of the question) that matches the color of the partner and showing the void.

The question is to bid with jump a suit not shown by any of the partners or opponent suit: 4♠/5♠ 5♣ 5♦ or 5♥. 

The ace of the void suit is not counted. 

Answers:

• • 1st step = 0 aces outside void;

  • 2nd step = 1 ace outside void;

  • 3rd step = 2 aces outside void;

  • 4th step = 3 aces outside void.

The convention is disabled if the length in the suit of the query is not excluded.