Problem p175

한국어

within 3, 7 legal points

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

Stones to capture: A9, B9, A8, B8

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 C8, White pass, Black A7, White pass, Black B7 (captures 4)
  2. Black C8, White D9, Black A7, White pass, Black B7 (captures 4)
  3. Black C8, White D8, Black A7, White pass, Black B7 (captures 4)
  4. Black C8, White A7, Black B7 (captures 5)
  5. Black C8, White B7, Black A7, White pass, Black C7 (captures 5)
  6. Black C8, White C7, Black A7, White pass, Black B7 (captures 4)
  7. Black C8, White D7, Black A7, White pass, Black B7 (captures 4)

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

  • Black D9, White survives even by passing.
  • Black D8, White survives even by passing.
  • Black A7, White answers at C8 and lives.
  • Black B7, White answers at C8 and lives.
  • Black C7, White survives even by passing.
  • Black D7, White survives even by passing.