| 
    Rule of 10 - When contemplating a penalty double beneath opponent's 
    game, consider the following criteria: 
      
        | 1. | Combined partnership HCP is 20+ |  
        | 2. | Misfit with 
        partner |  
        | 3. | Trump  winners 
        plus opponent's bidding level is 10+ |  
    Example: Assuming partnership holds 20+ HCP and no partnership fit.   
    You hold
    A Q x (2 winners) in Right Hand Opponent's major suit, with the 
    opponents continuing biding the suit at the 2 level (8 tricks).   
    Since 2 + 8 = 10, a penalty double is warranted. 
      
        | Opponents' Bidding Level | TricksRequired
 | Number of Trump winnersrequired to Double
 (assuming partnership misfit)
 |  
        | 1 | 6 + 1 = 7 | 10 - 7 = 3 |  
        | 2 | 6 + 2 = 8 | 10 - 8 = 2 |  
        | 3 | 6 + 3 = 9 | 10 - 9 = 1 |  
    Also see Environmental Factors |