{
  "contract": "probability-backtest-overfitting-example-v1",
  "publishedAt": "2026-09-16",
  "canonical": "/probability-backtest-overfitting",
  "sourceMatrix": "/research-data/probability-backtest-overfitting-example-2026-09-16.csv",
  "method": "Combinatorially Symmetric Cross-Validation using annualized Sharpe as the per-split strategy-selection statistic",
  "generator": {
    "distribution": "independent zero-edge Normal returns",
    "observations": 96,
    "strategies": 8,
    "dailyVolatility": 0.01,
    "seed": 35035,
    "roundedCsvDecimals": 8
  },
  "parameters": {
    "partitions": 8,
    "periodsPerYear": 252,
    "symmetricSplits": 70
  },
  "result": {
    "pboPercent": 45.714285714285715,
    "medianOosRelativeRank": 0.5555555555555556,
    "medianLogit": 0.22314355131420993,
    "meanOosSharpeOfIsWinner": -0.004442353562718636,
    "oosLossRatePercent": 42.857142857142854,
    "inSampleWinnerTieSplits": 0
  },
  "interpretation": "This fixed-seed example is a reproducibility fixture, not a universal null PBO estimate. PBO depends on the full strategy matrix, the selection statistic, the partitioning scheme, and the research process represented by the matrix."
}