| 
    Key Card Gerber (Mini-Max Gerber)  - A slam bidding variation from regular Gerber (when trump suit 
    has not been names), designed to increase the accuracy when considering the 
    potential to reach slam or grandslam.   This method recognizes 
    partner's Aces for slam controls and the "playability" (point range). In response to a bid of 4 Club invite (Gerber): 
      
        | Response | Meaning |  
        | 4D | 0 or 3 keys |  
        | 4H | 1 or 4 keys |  
        | 4S | 2 keys with a minimum 
        hand |  
        | 4N | 2 keys with a maximum 
        hand |  
    Also see Super Gerber |