{
  "generated": "2026-08-06T09:34:59.986Z",
  "revision": "v2 — after review by GM Noël Studer",
  "engine": "Stockfish 17, depth 12 (sf17 population)",
  "source_archive": "lichess_db_standard_rated_2025-03",
  "method": {
    "decisive_mistake": "last move after which the player was at a 2-pawn or worse deficit and never recovered",
    "changed_from_v1": "v1 used the largest single-ply evaluation drop, which over-weighted swings in already-decided positions",
    "phase_primary": "by material: endgame = 6 or fewer non-king non-pawn pieces (Lichess threshold); opening = 13+ such pieces; middlegame otherwise",
    "phase_secondary": "by move number, retained only for comparison with v1",
    "min_plies": 20,
    "excluded": {
      "too_short": 1451,
      "no_decisive_deficit": 3666,
      "deficit_created_by_opponent": 681
    },
    "confidence_intervals": "Wilson 95% on phase shares"
  },
  "results": {
    "sf17": {
      "700-899": {
        "games_with_a_decision": 1526,
        "median_decisive_move": 17,
        "decisive_ply": {
          "p25": 20,
          "median": 33,
          "p75": 50
        },
        "median_game_length_plies": 49,
        "median_pieces_at_mistake": 10,
        "phase_by_material": {
          "opening": 0.244,
          "middlegame": 0.495,
          "endgame": 0.261,
          "endgame_ci95": [
            0.239,
            0.283
          ],
          "opening_ci95": [
            0.224,
            0.267
          ],
          "n": 1526
        },
        "phase_by_move_number": {
          "opening": 0.335,
          "middlegame": 0.507,
          "endgame": 0.158,
          "n": 1526
        },
        "by_time_control": {
          "blitz": {
            "n": 760,
            "median_move": 17,
            "endgame_share": 0.267
          },
          "bullet": {
            "n": 320,
            "median_move": 14,
            "endgame_share": 0.15
          },
          "rapid": {
            "n": 443,
            "median_move": 19,
            "endgame_share": 0.33
          }
        },
        "median_drop_pawns": 6
      },
      "900-1099": {
        "games_with_a_decision": 1577,
        "median_decisive_move": 19,
        "decisive_ply": {
          "p25": 23,
          "median": 38,
          "p75": 54
        },
        "median_game_length_plies": 54,
        "median_pieces_at_mistake": 9,
        "phase_by_material": {
          "opening": 0.174,
          "middlegame": 0.528,
          "endgame": 0.298,
          "endgame_ci95": [
            0.276,
            0.321
          ],
          "opening_ci95": [
            0.156,
            0.193
          ],
          "n": 1577
        },
        "phase_by_move_number": {
          "opening": 0.279,
          "middlegame": 0.541,
          "endgame": 0.18,
          "n": 1577
        },
        "by_time_control": {
          "blitz": {
            "n": 770,
            "median_move": 19,
            "endgame_share": 0.314
          },
          "rapid": {
            "n": 375,
            "median_move": 20,
            "endgame_share": 0.304
          },
          "bullet": {
            "n": 426,
            "median_move": 18,
            "endgame_share": 0.268
          }
        },
        "median_drop_pawns": 5.68
      },
      "1100-1299": {
        "games_with_a_decision": 1639,
        "median_decisive_move": 20,
        "decisive_ply": {
          "p25": 25,
          "median": 40,
          "p75": 56
        },
        "median_game_length_plies": 56,
        "median_pieces_at_mistake": 9,
        "phase_by_material": {
          "opening": 0.166,
          "middlegame": 0.515,
          "endgame": 0.319,
          "endgame_ci95": [
            0.297,
            0.342
          ],
          "opening_ci95": [
            0.149,
            0.185
          ],
          "n": 1639
        },
        "phase_by_move_number": {
          "opening": 0.247,
          "middlegame": 0.547,
          "endgame": 0.206,
          "n": 1639
        },
        "by_time_control": {
          "bullet": {
            "n": 455,
            "median_move": 19,
            "endgame_share": 0.316
          },
          "rapid": {
            "n": 343,
            "median_move": 18,
            "endgame_share": 0.28
          },
          "blitz": {
            "n": 834,
            "median_move": 21,
            "endgame_share": 0.335
          }
        },
        "median_drop_pawns": 5.18
      },
      "1300-1499": {
        "games_with_a_decision": 1670,
        "median_decisive_move": 22,
        "decisive_ply": {
          "p25": 28,
          "median": 43,
          "p75": 59
        },
        "median_game_length_plies": 60,
        "median_pieces_at_mistake": 8,
        "phase_by_material": {
          "opening": 0.134,
          "middlegame": 0.532,
          "endgame": 0.334,
          "endgame_ci95": [
            0.311,
            0.357
          ],
          "opening_ci95": [
            0.119,
            0.151
          ],
          "n": 1670
        },
        "phase_by_move_number": {
          "opening": 0.19,
          "middlegame": 0.586,
          "endgame": 0.224,
          "n": 1670
        },
        "by_time_control": {
          "blitz": {
            "n": 855,
            "median_move": 22,
            "endgame_share": 0.342
          },
          "bullet": {
            "n": 560,
            "median_move": 21,
            "endgame_share": 0.305
          },
          "rapid": {
            "n": 251,
            "median_move": 22,
            "endgame_share": 0.367
          }
        },
        "median_drop_pawns": 5
      },
      "1500-1799": {
        "games_with_a_decision": 1660,
        "median_decisive_move": 23,
        "decisive_ply": {
          "p25": 31,
          "median": 46,
          "p75": 64
        },
        "median_game_length_plies": 63,
        "median_pieces_at_mistake": 8,
        "phase_by_material": {
          "opening": 0.113,
          "middlegame": 0.517,
          "endgame": 0.37,
          "endgame_ci95": [
            0.348,
            0.394
          ],
          "opening_ci95": [
            0.098,
            0.129
          ],
          "n": 1660
        },
        "phase_by_move_number": {
          "opening": 0.144,
          "middlegame": 0.575,
          "endgame": 0.281,
          "n": 1660
        },
        "by_time_control": {
          "rapid": {
            "n": 227,
            "median_move": 22,
            "endgame_share": 0.401
          },
          "blitz": {
            "n": 841,
            "median_move": 24,
            "endgame_share": 0.37
          },
          "bullet": {
            "n": 584,
            "median_move": 22,
            "endgame_share": 0.361
          }
        },
        "median_drop_pawns": 4.67
      },
      "1800-2000": {
        "games_with_a_decision": 1690,
        "median_decisive_move": 24,
        "decisive_ply": {
          "p25": 33,
          "median": 48,
          "p75": 66
        },
        "median_game_length_plies": 67,
        "median_pieces_at_mistake": 8,
        "phase_by_material": {
          "opening": 0.108,
          "middlegame": 0.525,
          "endgame": 0.367,
          "endgame_ci95": [
            0.345,
            0.391
          ],
          "opening_ci95": [
            0.094,
            0.123
          ],
          "n": 1690
        },
        "phase_by_move_number": {
          "opening": 0.112,
          "middlegame": 0.573,
          "endgame": 0.315,
          "n": 1690
        },
        "by_time_control": {
          "blitz": {
            "n": 779,
            "median_move": 25,
            "endgame_share": 0.365
          },
          "bullet": {
            "n": 701,
            "median_move": 24,
            "endgame_share": 0.369
          },
          "rapid": {
            "n": 205,
            "median_move": 24,
            "endgame_share": 0.366
          }
        },
        "median_drop_pawns": 4.33
      }
    },
    "lichess": {
      "700-899": {
        "games_with_a_decision": 1680,
        "median_decisive_move": 16,
        "decisive_ply": {
          "p25": 19,
          "median": 31,
          "p75": 45
        },
        "median_game_length_plies": 52,
        "median_pieces_at_mistake": 10,
        "phase_by_material": {
          "opening": 0.276,
          "middlegame": 0.538,
          "endgame": 0.186,
          "endgame_ci95": [
            0.168,
            0.205
          ],
          "opening_ci95": [
            0.255,
            0.298
          ],
          "n": 1680
        },
        "phase_by_move_number": {
          "opening": 0.374,
          "middlegame": 0.524,
          "endgame": 0.102,
          "n": 1680
        },
        "by_time_control": {
          "rapid": {
            "n": 717,
            "median_move": 15,
            "endgame_share": 0.177
          },
          "blitz": {
            "n": 698,
            "median_move": 17,
            "endgame_share": 0.212
          },
          "bullet": {
            "n": 263,
            "median_move": 14,
            "endgame_share": 0.141
          }
        },
        "median_drop_pawns": 5.58
      },
      "900-1099": {
        "games_with_a_decision": 3893,
        "median_decisive_move": 17,
        "decisive_ply": {
          "p25": 21,
          "median": 33,
          "p75": 48
        },
        "median_game_length_plies": 54,
        "median_pieces_at_mistake": 10,
        "phase_by_material": {
          "opening": 0.234,
          "middlegame": 0.55,
          "endgame": 0.217,
          "endgame_ci95": [
            0.204,
            0.23
          ],
          "opening_ci95": [
            0.221,
            0.247
          ],
          "n": 3893
        },
        "phase_by_move_number": {
          "opening": 0.33,
          "middlegame": 0.556,
          "endgame": 0.114,
          "n": 3893
        },
        "by_time_control": {
          "rapid": {
            "n": 1574,
            "median_move": 16,
            "endgame_share": 0.216
          },
          "bullet": {
            "n": 717,
            "median_move": 17,
            "endgame_share": 0.195
          },
          "blitz": {
            "n": 1558,
            "median_move": 18,
            "endgame_share": 0.229
          },
          "classical": {
            "n": 44,
            "median_move": 13,
            "endgame_share": 0.136
          }
        },
        "median_drop_pawns": 5.1
      },
      "1100-1299": {
        "games_with_a_decision": 5431,
        "median_decisive_move": 18,
        "decisive_ply": {
          "p25": 23,
          "median": 36,
          "p75": 51
        },
        "median_game_length_plies": 56,
        "median_pieces_at_mistake": 10,
        "phase_by_material": {
          "opening": 0.201,
          "middlegame": 0.56,
          "endgame": 0.238,
          "endgame_ci95": [
            0.227,
            0.25
          ],
          "opening_ci95": [
            0.191,
            0.212
          ],
          "n": 5431
        },
        "phase_by_move_number": {
          "opening": 0.281,
          "middlegame": 0.581,
          "endgame": 0.138,
          "n": 5431
        },
        "by_time_control": {
          "blitz": {
            "n": 2146,
            "median_move": 19,
            "endgame_share": 0.26
          },
          "rapid": {
            "n": 2200,
            "median_move": 17,
            "endgame_share": 0.221
          },
          "classical": {
            "n": 74,
            "median_move": 17,
            "endgame_share": 0.23
          },
          "bullet": {
            "n": 1011,
            "median_move": 18,
            "endgame_share": 0.227
          }
        },
        "median_drop_pawns": 4.91
      },
      "1300-1499": {
        "games_with_a_decision": 6792,
        "median_decisive_move": 19,
        "decisive_ply": {
          "p25": 25,
          "median": 38,
          "p75": 53
        },
        "median_game_length_plies": 58,
        "median_pieces_at_mistake": 10,
        "phase_by_material": {
          "opening": 0.174,
          "middlegame": 0.568,
          "endgame": 0.258,
          "endgame_ci95": [
            0.248,
            0.268
          ],
          "opening_ci95": [
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            0.184
          ],
          "n": 6792
        },
        "phase_by_move_number": {
          "opening": 0.245,
          "middlegame": 0.59,
          "endgame": 0.165,
          "n": 6792
        },
        "by_time_control": {
          "blitz": {
            "n": 2709,
            "median_move": 20,
            "endgame_share": 0.283
          },
          "bullet": {
            "n": 1431,
            "median_move": 18,
            "endgame_share": 0.233
          },
          "rapid": {
            "n": 2508,
            "median_move": 19,
            "endgame_share": 0.248
          },
          "classical": {
            "n": 143,
            "median_move": 17,
            "endgame_share": 0.203
          }
        },
        "median_drop_pawns": 4.62
      },
      "1500-1799": {
        "games_with_a_decision": 10077,
        "median_decisive_move": 21,
        "decisive_ply": {
          "p25": 28,
          "median": 41,
          "p75": 57
        },
        "median_game_length_plies": 60,
        "median_pieces_at_mistake": 9,
        "phase_by_material": {
          "opening": 0.15,
          "middlegame": 0.568,
          "endgame": 0.283,
          "endgame_ci95": [
            0.274,
            0.291
          ],
          "opening_ci95": [
            0.143,
            0.157
          ],
          "n": 10077
        },
        "phase_by_move_number": {
          "opening": 0.185,
          "middlegame": 0.609,
          "endgame": 0.206,
          "n": 10077
        },
        "by_time_control": {
          "bullet": {
            "n": 2202,
            "median_move": 20,
            "endgame_share": 0.265
          },
          "blitz": {
            "n": 4248,
            "median_move": 21,
            "endgame_share": 0.295
          },
          "rapid": {
            "n": 3330,
            "median_move": 20,
            "endgame_share": 0.283
          },
          "classical": {
            "n": 278,
            "median_move": 20,
            "endgame_share": 0.237
          }
        },
        "median_drop_pawns": 4.29
      },
      "1800-2000": {
        "games_with_a_decision": 5725,
        "median_decisive_move": 22,
        "decisive_ply": {
          "p25": 31,
          "median": 44,
          "p75": 60
        },
        "median_game_length_plies": 63,
        "median_pieces_at_mistake": 9,
        "phase_by_material": {
          "opening": 0.131,
          "middlegame": 0.566,
          "endgame": 0.303,
          "endgame_ci95": [
            0.292,
            0.315
          ],
          "opening_ci95": [
            0.122,
            0.14
          ],
          "n": 5725
        },
        "phase_by_move_number": {
          "opening": 0.139,
          "middlegame": 0.621,
          "endgame": 0.24,
          "n": 5725
        },
        "by_time_control": {
          "blitz": {
            "n": 2662,
            "median_move": 23,
            "endgame_share": 0.307
          },
          "bullet": {
            "n": 1294,
            "median_move": 21,
            "endgame_share": 0.285
          },
          "rapid": {
            "n": 1607,
            "median_move": 22,
            "endgame_share": 0.317
          },
          "classical": {
            "n": 147,
            "median_move": 23,
            "endgame_share": 0.279
          }
        },
        "median_drop_pawns": 4
      }
    }
  }
}