{
  "test_years": [
    2018,
    2019,
    2020,
    2021,
    2022,
    2023,
    2024,
    2025,
    2026
  ],
  "half_life_days": 180.0,
  "total_test_matches": 8265,
  "neutral_test_matches": 2660,
  "folds": [
    {
      "test_year": 2018,
      "train_matches": 2829,
      "test_matches": 895,
      "neutral_test_matches": 245,
      "fitted_params": {
        "intercept": 0.11480792473373332,
        "elo_scale": 0.0020289671408902678,
        "home_advantage_elo": 96.66494847608217,
        "rho": -0.10325063882286081
      },
      "mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681347,
          "brier": 0.6666666666666677,
          "rps": 0.2349472377405314
        },
        "current": {
          "log_loss": 0.9023609429969789,
          "brier": 0.5327335616980057,
          "rps": 0.17345577301787155
        },
        "fitted": {
          "log_loss": 0.8573809678608475,
          "brier": 0.5060835684039483,
          "rps": 0.16129081700055478
        }
      },
      "neutral_mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681078,
          "brier": 0.666666666666666,
          "rps": 0.23287981859410511
        },
        "current": {
          "log_loss": 0.8834315475603629,
          "brier": 0.5228932563420171,
          "rps": 0.16550343317192542
        },
        "fitted": {
          "log_loss": 0.8643892036200318,
          "brier": 0.5157402284621485,
          "rps": 0.1621838008080314
        }
      }
    },
    {
      "test_year": 2019,
      "train_matches": 3724,
      "test_matches": 1151,
      "neutral_test_matches": 353,
      "fitted_params": {
        "intercept": 0.07655270209555426,
        "elo_scale": 0.0021520627736449803,
        "home_advantage_elo": 104.35377163519401,
        "rho": -0.09333056692211965
      },
      "mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681413,
          "brier": 0.6666666666666591,
          "rps": 0.24230138044212424
        },
        "current": {
          "log_loss": 0.8056111798212608,
          "brier": 0.4669964990094554,
          "rps": 0.1542259079723281
        },
        "fitted": {
          "log_loss": 0.7623887448033608,
          "brier": 0.4436091602690203,
          "rps": 0.14349092866806895
        }
      },
      "neutral_mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681076,
          "brier": 0.6666666666666633,
          "rps": 0.23575700346238562
        },
        "current": {
          "log_loss": 0.9035421998672475,
          "brier": 0.5318945223380837,
          "rps": 0.17509914280333874
        },
        "fitted": {
          "log_loss": 0.8918610713311597,
          "brier": 0.5250460714170974,
          "rps": 0.17242426076070852
        }
      }
    },
    {
      "test_year": 2020,
      "train_matches": 4875,
      "test_matches": 366,
      "neutral_test_matches": 50,
      "fitted_params": {
        "intercept": 0.08882969340736556,
        "elo_scale": 0.0021691318930572856,
        "home_advantage_elo": 87.14925981971481,
        "rho": -0.022682480183322452
      },
      "mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681076,
          "brier": 0.6666666666666631,
          "rps": 0.23451730418943506
        },
        "current": {
          "log_loss": 0.9057996612707523,
          "brier": 0.5350331124220667,
          "rps": 0.17316146306007385
        },
        "fitted": {
          "log_loss": 0.8880460395185107,
          "brier": 0.5245472137423897,
          "rps": 0.1687037965936433
        }
      },
      "neutral_mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681091,
          "brier": 0.666666666666667,
          "rps": 0.24111111111111122
        },
        "current": {
          "log_loss": 0.9038213868459777,
          "brier": 0.5293136355860008,
          "rps": 0.1820028424646411
        },
        "fitted": {
          "log_loss": 0.8910762716994022,
          "brier": 0.5204344668752423,
          "rps": 0.1785644247095937
        }
      }
    },
    {
      "test_year": 2021,
      "train_matches": 5241,
      "test_matches": 1131,
      "neutral_test_matches": 372,
      "fitted_params": {
        "intercept": 0.09894524890544283,
        "elo_scale": 0.002086079271632328,
        "home_advantage_elo": 71.854097236582,
        "rho": -0.07719874643271779
      },
      "mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681409,
          "brier": 0.6666666666666596,
          "rps": 0.24034777483053016
        },
        "current": {
          "log_loss": 0.7771281328670586,
          "brier": 0.4494107978358997,
          "rps": 0.14187993077918162
        },
        "fitted": {
          "log_loss": 0.7303453228987331,
          "brier": 0.4226998299669378,
          "rps": 0.12981376058981092
        }
      },
      "neutral_mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681076,
          "brier": 0.666666666666663,
          "rps": 0.2396953405017915
        },
        "current": {
          "log_loss": 0.7752914985633477,
          "brier": 0.44538900996736913,
          "rps": 0.1396289557189527
        },
        "fitted": {
          "log_loss": 0.7424352387197773,
          "brier": 0.4277416309134095,
          "rps": 0.13198354285045627
        }
      }
    },
    {
      "test_year": 2022,
      "train_matches": 6372,
      "test_matches": 985,
      "neutral_test_matches": 381,
      "fitted_params": {
        "intercept": 0.08186883125481959,
        "elo_scale": 0.002241281090538066,
        "home_advantage_elo": 74.43744515107814,
        "rho": -0.09478096119163382
      },
      "mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681373,
          "brier": 0.6666666666666642,
          "rps": 0.23953750705019464
        },
        "current": {
          "log_loss": 0.8761344289777128,
          "brier": 0.5133523843352195,
          "rps": 0.1706774554386513
        },
        "fitted": {
          "log_loss": 0.833657111049536,
          "brier": 0.488081624725104,
          "rps": 0.15921570644885422
        }
      },
      "neutral_mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681076,
          "brier": 0.6666666666666629,
          "rps": 0.23665791776027933
        },
        "current": {
          "log_loss": 0.8657594659735913,
          "brier": 0.5056354267716627,
          "rps": 0.16380135962473727
        },
        "fitted": {
          "log_loss": 0.8416080431008207,
          "brier": 0.49252926430948385,
          "rps": 0.15831754337007392
        }
      }
    },
    {
      "test_year": 2023,
      "train_matches": 7357,
      "test_matches": 1059,
      "neutral_test_matches": 301,
      "fitted_params": {
        "intercept": 0.09590587998895488,
        "elo_scale": 0.002136418937922069,
        "home_advantage_elo": 80.8624491992637,
        "rho": -0.01817599719515351
      },
      "mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681393,
          "brier": 0.6666666666666617,
          "rps": 0.2403210576015079
        },
        "current": {
          "log_loss": 0.8164324637949784,
          "brier": 0.4761251590147837,
          "rps": 0.15479442502291524
        },
        "fitted": {
          "log_loss": 0.78464414371364,
          "brier": 0.45951898347685194,
          "rps": 0.14722498614337617
        }
      },
      "neutral_mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681078,
          "brier": 0.6666666666666644,
          "rps": 0.23791066814322662
        },
        "current": {
          "log_loss": 0.8342171896940022,
          "brier": 0.4853941084027272,
          "rps": 0.15585628251257372
        },
        "fitted": {
          "log_loss": 0.810164720860691,
          "brier": 0.47283004252787125,
          "rps": 0.15028013851884245
        }
      }
    },
    {
      "test_year": 2024,
      "train_matches": 8416,
      "test_matches": 1292,
      "neutral_test_matches": 496,
      "fitted_params": {
        "intercept": 0.135784402714181,
        "elo_scale": 0.002062972962563908,
        "home_advantage_elo": 86.575382309738,
        "rho": -0.08165901384717028
      },
      "mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681438,
          "brier": 0.6666666666666557,
          "rps": 0.235595115239074
        },
        "current": {
          "log_loss": 0.8526359403098033,
          "brier": 0.49941486960892056,
          "rps": 0.15859748254285871
        },
        "fitted": {
          "log_loss": 0.8217710854614934,
          "brier": 0.48382352093062225,
          "rps": 0.15158860276123537
        }
      },
      "neutral_mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681111,
          "brier": 0.666666666666668,
          "rps": 0.22939068100358312
        },
        "current": {
          "log_loss": 0.8834120721785726,
          "brier": 0.5214199459292324,
          "rps": 0.16100681571387543
        },
        "fitted": {
          "log_loss": 0.8697466901921638,
          "brier": 0.5158284711675852,
          "rps": 0.15862363420743003
        }
      }
    },
    {
      "test_year": 2025,
      "train_matches": 9708,
      "test_matches": 1035,
      "neutral_test_matches": 319,
      "fitted_params": {
        "intercept": 0.13154596600905927,
        "elo_scale": 0.002036860739245838,
        "home_advantage_elo": 81.47927268898184,
        "rho": -0.11197216228672728
      },
      "mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681386,
          "brier": 0.6666666666666625,
          "rps": 0.24057971014492466
        },
        "current": {
          "log_loss": 0.7880248007600671,
          "brier": 0.4567673295937216,
          "rps": 0.14619068635740878
        },
        "fitted": {
          "log_loss": 0.7490973486843856,
          "brier": 0.4377864820871933,
          "rps": 0.13752468930374132
        }
      },
      "neutral_mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681078,
          "brier": 0.666666666666664,
          "rps": 0.2349355625217695
        },
        "current": {
          "log_loss": 0.8283942270934415,
          "brier": 0.48593502970010505,
          "rps": 0.15095687011092038
        },
        "fitted": {
          "log_loss": 0.8006791374196626,
          "brier": 0.4739426425559977,
          "rps": 0.14522519677837512
        }
      }
    },
    {
      "test_year": 2026,
      "train_matches": 10743,
      "test_matches": 351,
      "neutral_test_matches": 143,
      "fitted_params": {
        "intercept": 0.14002451697534277,
        "elo_scale": 0.002035817689422612,
        "home_advantage_elo": 71.82836996410468,
        "rho": -0.11346576437055059
      },
      "mean_scores": {
        "uniform": {
          "log_loss": 1.0986122886681076,
          "brier": 0.6666666666666633,
          "rps": 0.23789173789173768
        },
        "current": {
          "log_loss": 0.8373907540633281,
          "brier": 0.4844743976711385,
          "rps": 0.15558773214039767
        },
        "fitted": {
          "log_loss": 0.8010975523248702,
          "brier": 0.46545804008130004,
          "rps": 0.14724905524780943
        }
      },
      "neutral_mean_scores": {
        "uniform": {
          "log_loss": 1.098612288668108,
          "brier": 0.6666666666666675,
          "rps": 0.23931623931623966
        },
        "current": {
          "log_loss": 0.836343534499324,
          "brier": 0.48346963528722114,
          "rps": 0.15755513737164847
        },
        "fitted": {
          "log_loss": 0.8038171175434251,
          "brier": 0.46573230600770044,
          "rps": 0.15013688009902199
        }
      }
    }
  ],
  "overall_mean_scores": {
    "uniform": {
      "log_loss": 1.0986122886681369,
      "brier": 0.6666666666666613,
      "rps": 0.2388586408550082
    },
    "current": {
      "log_loss": 0.8329166311312037,
      "brier": 0.48594465732512054,
      "rps": 0.15722582282290334
    },
    "fitted": {
      "log_loss": 0.7944622460875409,
      "brier": 0.46492105251553006,
      "rps": 0.14769412833147244
    }
  },
  "neutral_mean_scores": {
    "uniform": {
      "log_loss": 1.0986122886681082,
      "brier": 0.6666666666666647,
      "rps": 0.23542188805346673
    },
    "current": {
      "log_loss": 0.8541246747458301,
      "brier": 0.4998279915063266,
      "rps": 0.15912275114447516
    },
    "fitted": {
      "log_loss": 0.8321846360289137,
      "brier": 0.4888921301366171,
      "rps": 0.15438117832100154
    }
  },
  "calibration_home_win": [
    {
      "predicted_range": [
        0.0,
        0.1
      ],
      "n": 564,
      "predicted_mean": 0.04875281109133798,
      "observed_home_win_rate": 0.05673758865248227
    },
    {
      "predicted_range": [
        0.1,
        0.2
      ],
      "n": 657,
      "predicted_mean": 0.15091809523379324,
      "observed_home_win_rate": 0.1917808219178082
    },
    {
      "predicted_range": [
        0.2,
        0.3
      ],
      "n": 846,
      "predicted_mean": 0.25165383909489764,
      "observed_home_win_rate": 0.3203309692671395
    },
    {
      "predicted_range": [
        0.3,
        0.4
      ],
      "n": 983,
      "predicted_mean": 0.35131798427317085,
      "observed_home_win_rate": 0.4659206510681587
    },
    {
      "predicted_range": [
        0.4,
        0.5
      ],
      "n": 986,
      "predicted_mean": 0.4503357401106465,
      "observed_home_win_rate": 0.5567951318458418
    },
    {
      "predicted_range": [
        0.5,
        0.6
      ],
      "n": 1005,
      "predicted_mean": 0.5499731291510652,
      "observed_home_win_rate": 0.6626865671641791
    },
    {
      "predicted_range": [
        0.6,
        0.7
      ],
      "n": 915,
      "predicted_mean": 0.6504787505848735,
      "observed_home_win_rate": 0.7289617486338797
    },
    {
      "predicted_range": [
        0.7,
        0.8
      ],
      "n": 859,
      "predicted_mean": 0.7489004240433575,
      "observed_home_win_rate": 0.830034924330617
    },
    {
      "predicted_range": [
        0.8,
        0.9
      ],
      "n": 745,
      "predicted_mean": 0.8493848408730554,
      "observed_home_win_rate": 0.8966442953020134
    },
    {
      "predicted_range": [
        0.9,
        1.0
      ],
      "n": 705,
      "predicted_mean": 0.9430183315798715,
      "observed_home_win_rate": 0.9475177304964539
    }
  ],
  "ship_gate": {
    "fitted_beats_uniform_log_loss": true,
    "fitted_beats_current_log_loss": true,
    "fitted_beats_current_neutral_log_loss": true,
    "ship": true,
    "criterion": "The fitted Dixon-Coles Elo model must have a lower mean log loss than both the uniform baseline and the model previously shipped in world_cup/forecasting.py, both overall and on neutral-venue matches, across walk-forward test folds (2018-2026, no fold trained on its own test data)."
  }
}