96/05/24

                                  RKC BLACKWOOD
                                 ^^^^^^^^^^^^^^^

  1. Applied Situation

    4NT is RKC Blackwood

      1) After obvious 8-card trump fit at least.
      2) After same suit rebid by Strong Opener.
         (i.e. 2C Opener / Jump-Shift Responder )
      3) Jump to 4NT just after suit bid.

    When 2-suit-fit is found, 2nd suit is Trump Suit.

    4NT is natural and not RKC Blackwood when below ;

      1) Obvious 8-card trump fit is not found.
      2) Last bid is Natural NT.
      3) 4NT by player who has shown negative attitude toward slam.
      4) 4NT by player who can make natural slam try.

    OPN   RSP
    1H    2D
    3H    3NT
    4NT
    ~~~
    4NT is RKC Blackwood for HEA, because Opener has set HEA as trump.

    OPN   RSP
    1H    2D
    2H    3NT
    4NT
    ~~~
    4NT is Natural INV to 6NT, because no trump suit is set.

  2. Subsequent Sequence After RKC Blackwood

   2-1. Reply to RKC Blackwood

    5C    = 1 / 4 Key Card(s)
    5D    = 0 / 3 Key Card(s)
    5H    = 2 / 5 Key Cards, no Trump Queen or 10-card fit
    5S    = 2 / 5 Key Cards, with Trump Queen or 10-card fit
    5NT   = 2 Key Cards, with Trump Queen, with VOID
    6X    = 1 Key Card, with Trump Queen, VOID showing

   2-2. After 5C/5D Reply

    Next Step except Trump = ASK for Trump Queen
        --1st Step = no Trump Queen or 10-card fit
        --2nd Step = with Trump Queen or 10-card fit

   2-3. After 5X Reply

    5NT   = ASK for King ; promises all 5 Key Cards & Trump Queen
        --6X    = King showing up the line
    Suit  = ASK for 3rd CON ( Queen or doubleton with extra Trump )

   2-4. Over Opponent's Intervening

    2-4-1. Below Our 5-level Suit

    Dbl   = Roman DOPI ; 0 / 3 Key Card(s)
    Pass  = Roman DOPI ; 1 / 4 Key Card(s)
    1st Step = Roman DOPI ; 2 / 5 Key Cards, no Trump Queen or 10-card fit
    2nd Step = Roman DOPI ; 2 / 5 Key Cards, with Trump Queen or 10-card fit

    2-4-2. Above Our 5-level Suit

    Dbl   = DEPO ; 0 / 2 / 4 Key Card(s)
    Pass  = DEPO ; 1 / 3 / 5 Key Card(s)