Problem p004

한국어

within 3, 8 legal points

Black to play. Capture the marked white stones within 3 moves.

Stones to capture: B7, C7, D7

Black to play.

Why this is the move

White has 8 possible answers. Every one of them is listed below with the way Black captures. These are search results, not written commentary.

  1. Black B8, White pass, Black C8, White pass, Black D8 (captures 3)
  2. Black B8, White A9, Black C8, White pass, Black D8 (captures 3)
  3. Black B8, White B9, Black C8, White pass, Black D8 (captures 3)
  4. Black B8, White C9, Black C8, White pass, Black D8 (captures 3)
  5. Black B8, White D9, Black C8, White pass, Black D8 (captures 3)
  6. Black B8, White A8, Black C8, White pass, Black D8 (captures 3)
  7. Black B8, White C8, Black C9, White pass, Black D8 (captures 4)
  8. Black B8, White D8, Black D9, White pass, Black C8 (captures 4)

Black has 8 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 B9, White survives even by passing.
  • Black C9, White survives even by passing.
  • Black D9, White survives even by passing.
  • Black A8, White survives even by passing.
  • Black C8, White answers at B8 and lives.
  • Black D8, White answers at C9 and lives.