{
  "patternType": "SKEWER",
  "description": "Bishop skewer forcing the king off the diagonal so the trailing queen can be captured.",
  "cases": [
    {
      "id": "skewer_bishop_on_long_diagonal",
      "initialFen": "7q/6k1/8/8/8/8/1B6/6K1 w - - 0 1",
      "sideToMove": "white",
      "bestMove": { "san": "Bc3+", "uci": "b2c3" },
      "resultingFen": "7q/6k1/8/8/8/2B5/8/6K1 b - - 1 1",
      "expectedPattern": {
        "type": "SKEWER",
        "side": "white",
        "attackerSquares": ["c3"],
        "targetSquares": ["g7", "h8"],
        "keySquares": ["g7"],
        "explanationKey": "king_in_front_of_queen"
      },
      "context": "Minimal material: the move Bc3+ attacks the king on g7; after the king moves the queen on h8 is lost.",
      "tags": ["endgame", "long_diagonal"]
    }
  ]
}