Problem p111

한국어

within 2, 7 legal points

Black to play. Capture the marked white stones within 2 moves.

Stones to capture: C9, D9, D8, D7

Black to play.

Why this is the move

White has 7 possible answers. Every one of them is listed below with the way Black captures. These are search results, not written commentary.

  1. Black B9, White pass, Black C7 (captures 4)
  2. Black B9, White A9, Black C7 (captures 4)
  3. Black B9, White A8, Black C7 (captures 4)
  4. Black B9, White B8, Black C7 (captures 4)
  5. Black B9, White A7, Black C7 (captures 4)
  6. Black B9, White B7, Black C7 (captures 4)
  7. Black B9, White C7, Black B7 (captures 5)

Black has 7 legal points here and exactly one of them captures. White answers the others as shown and survives.

  • Black A9, White survives even by passing.
  • Black A8, White survives even by passing.
  • Black B8, White survives even by passing.
  • Black A7, White survives even by passing.
  • Black B7, White survives even by passing.
  • Black C7, White answers at B9 and lives.