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    Responsive Double 
    - When Opponents Bid And Raise (OBAR) 
        in one suit over partner's interceding overcall, a 
        popular treatment by advancer is the Responsive Double.  The 
        Responsive Double shows length and values in the unbid suits with values similar to 
    the Negative Double.   Common 
    strength requirements for the Responsive Double are similar to the Negative 
        Double, considering 
        Environmental Factors: 
          
        | Bidding Level | Points |  
        | 1 Major or 2 Minor | 8 |  
        | 2 Major | 9+ |  
        | 3 Level | 10+ |  Examples 
        of auctions that illustrate Responsive Doubles: 
          
            | 1. | (1D) -    X    
            - (2D)  -   X; |  
            | 2. | (1C) -   1H   - 
            (2C)  -   X; |  
            | 3. |    P    - 
            (1H) - (1S)  - (2H);(X)
 |  
            | 4. | (1S) -   2C   - 
            (2S)   -   X; |  
            | 5. | (1D) -  1S    - 
            (3D)  -   X;  OBAR jump by opponent 
            which could be weak/strong,Responsive Double still "on" here, but see bottom
 |  Examples 
        of auctions that are not Responsive Doubles: 
          
            | 1. | (1D) - 1N - (2D) - X;   Agreement needed (Penalty, Transfer, or Takeout) |  
            | 2. | (1C) - 1H - (1S)  - X;   
            No OBAR, agreement needed (Penalty or Takeout) |  
            | 3. | (1C) - 2H - (3C)  - X;  
            OBAR irrelevant with partner's preemptive jump (as Inverted Minors), 
            thus the Double is for penalty
 |  
        Partnership agreements needed here: 
          
            |  | Classic Approach | Modern Approach |  
            | 1. | (2D) - 2H - (3D)  - X; | OBAR "off" with 
            preemptive opening bid, thus Penalty | Responsive, opponents' 
            should not own auction with preemptive bidding |  
            | 2. | (3D) - X - (4D) - ?; | Same | Still Responsive, but 
            how high - 3S ?   4D ? |  Also see 
        other Doubles, particularly Takeout Double,
        Negative Double, and books on 
    Doubles |