{
 "license": "CC BY 4.0",
 "kind": "council-power-sensitivity",
 "generated": "2026-10-23T14:53:38Z",
 "rule": "Dated 22.10.2026. min_difference = (z_a + z_b) sd sqrt((1 + (k-1) rho) / (k sessions)) with alpha 0.05 two-sided, power 0.8, k = 12 forecasts a session (council_stats.min_detectable_brier, the formula of power_brier). The grid is fixed in advance (sd 0.05-0.20, rho 0-0.5); `book` = the sd and rho that power_brier uses now (measured on the book when it has enough, else assumed - the source is written beside). history = one entry per UTC day, kept across builds.",
 "reference": 0.25,
 "forecasts_per_session": 12,
 "sessions": [
  52,
  126
 ],
 "book": {
  "sd_loss": 0.0753,
  "sd_source": "measured on the book (365 forecasts of the seats)",
  "rho_losses": 0.41,
  "rho_source": "rho from the pooled runs; per-session rho from 5 sessions",
  "min_difference_52": 0.0198,
  "min_difference_126": 0.0127
 },
 "sensitivity": [
  {
   "sd_loss": 0.05,
   "rho_losses": 0.0,
   "min_difference_52": 0.0056,
   "min_difference_126": 0.0036
  },
  {
   "sd_loss": 0.05,
   "rho_losses": 0.1,
   "min_difference_52": 0.0081,
   "min_difference_126": 0.0052
  },
  {
   "sd_loss": 0.05,
   "rho_losses": 0.2,
   "min_difference_52": 0.01,
   "min_difference_126": 0.0064
  },
  {
   "sd_loss": 0.05,
   "rho_losses": 0.3,
   "min_difference_52": 0.0116,
   "min_difference_126": 0.0075
  },
  {
   "sd_loss": 0.05,
   "rho_losses": 0.5,
   "min_difference_52": 0.0143,
   "min_difference_126": 0.0092
  },
  {
   "sd_loss": 0.1,
   "rho_losses": 0.0,
   "min_difference_52": 0.0112,
   "min_difference_126": 0.0072
  },
  {
   "sd_loss": 0.1,
   "rho_losses": 0.1,
   "min_difference_52": 0.0163,
   "min_difference_126": 0.0104
  },
  {
   "sd_loss": 0.1,
   "rho_losses": 0.2,
   "min_difference_52": 0.0201,
   "min_difference_126": 0.0129
  },
  {
   "sd_loss": 0.1,
   "rho_losses": 0.3,
   "min_difference_52": 0.0233,
   "min_difference_126": 0.0149
  },
  {
   "sd_loss": 0.1,
   "rho_losses": 0.5,
   "min_difference_52": 0.0286,
   "min_difference_126": 0.0184
  },
  {
   "sd_loss": 0.15,
   "rho_losses": 0.0,
   "min_difference_52": 0.0168,
   "min_difference_126": 0.0108
  },
  {
   "sd_loss": 0.15,
   "rho_losses": 0.1,
   "min_difference_52": 0.0244,
   "min_difference_126": 0.0157
  },
  {
   "sd_loss": 0.15,
   "rho_losses": 0.2,
   "min_difference_52": 0.0301,
   "min_difference_126": 0.0193
  },
  {
   "sd_loss": 0.15,
   "rho_losses": 0.3,
   "min_difference_52": 0.0349,
   "min_difference_126": 0.0224
  },
  {
   "sd_loss": 0.15,
   "rho_losses": 0.5,
   "min_difference_52": 0.0429,
   "min_difference_126": 0.0276
  },
  {
   "sd_loss": 0.2,
   "rho_losses": 0.0,
   "min_difference_52": 0.0224,
   "min_difference_126": 0.0144
  },
  {
   "sd_loss": 0.2,
   "rho_losses": 0.1,
   "min_difference_52": 0.0325,
   "min_difference_126": 0.0209
  },
  {
   "sd_loss": 0.2,
   "rho_losses": 0.2,
   "min_difference_52": 0.0401,
   "min_difference_126": 0.0258
  },
  {
   "sd_loss": 0.2,
   "rho_losses": 0.3,
   "min_difference_52": 0.0465,
   "min_difference_126": 0.0299
  },
  {
   "sd_loss": 0.2,
   "rho_losses": 0.5,
   "min_difference_52": 0.0572,
   "min_difference_126": 0.0367
  }
 ],
 "history": [
  {
   "day": "2026-10-22",
   "sd_loss": 0.0753,
   "rho_losses": 0.43,
   "min_difference_52": 0.0202,
   "min_difference_126": 0.013
  },
  {
   "day": "2026-10-23",
   "sd_loss": 0.0753,
   "rho_losses": 0.41,
   "min_difference_52": 0.0198,
   "min_difference_126": 0.0127
  }
 ],
 "snapshot_id": "81bb52dea9cac906f145233bc63ec37e702106dd0945b666bf45e980571ee447",
 "snapshot_run": "2026-10-23-am"
}