| 
    Mathe - An elementary defensive system against 
    opponents' Big Club system to show a two-suited hand.  
      
        | Bid | Meaning |  
        |  |   |  
        | (1C) - 1D | Natural, showing Diamonds |  
        | (1C) - 1H | Natural, showing Hearts |  
        | (1C) - 1S | Natural, showing Spades |  
        | (1C) - X | Artificial, showing both 
        Majors (4+/4+ or greater, e.g. vulnerable) |  
        | (1C) - 1N | Artificial, showing both 
        Minors (4+/4+ or greater, e.g. vulnerable) |  
        | (1C) - 1N | Artificial, showing both 
        Minors with longer suits (often preemptive) |    |