{
  "series_id": "wr-target-share-stability",
  "version": "1.0",
  "question": "How many completed team games are needed for a wide receiver's observed target share to predict his share over the next four team games reliably?",
  "hypothesis": "Observed target share over a window of at least 4 completed team games predicts the next-four-game target share with held-out MAE at most 6 percentage points and at least 0.5 percentage points better than a prior-season target-share baseline; the full error curve is reported regardless of whether any window qualifies.",
  "estimand": "Held-out mean absolute error (percentage points) of next-four-team-game target share predictions, by observation window length (1, 2, 3, 4, 6, 8 team games), with paired improvement over the prior-season baseline.",
  "population": "All NFL wide receivers appearing in regular-season weekly player statistics from 2018 through the latest fully completed season (2025). WR eligibility is established only from information available within the observation window (position recorded as WR in the window's games); later zero-target games and absences are included; no future appearance or future target minimum is imposed. Postseason rows and future schedule rows are excluded. Season, week, player_id, position, and team fields are reconciled across files.",
  "outcomes": [
    "Primary: next-four-team-game target share, defined as the player's summed targets divided by all reported player targets for his team summed over the same four team games (RB and TE targets included in the denominator; untargeted pass attempts excluded). Targets are summed before dividing; weekly shares with unequal denominators are never averaged. The full-season target share is never used as the outcome."
  ],
  "features": [
    "Observed target share over the observation window (summed targets / summed team targets over the window's team games, same denominator definition).",
    "Training-only shrinkage estimate of target share (shrinkage parameters fit on earlier seasons only).",
    "Prior-season target-share baseline, with a training-only fallback (earlier-season WR mean) for players new to the data.",
    "Observation window lengths: 1, 2, 3, 4, 6, and 8 team games, strictly disjoint from the outcome window; team-game order and byes determined from the schedule file."
  ],
  "temporal_split": "Feature and outcome windows are strictly disjoint within each player-season. Shrinkage parameters and baseline fallbacks are fit using earlier seasons only. Evaluation is rolling over future seasons, with each of the final two completed seasons (2024 and 2025) reported separately as well as pooled. No outcome-window information is used in feature construction or eligibility.",
  "baselines": [
    "Prior-season target-share baseline with training-only fallback for new players; error reported explicitly per window.",
    "Earlier-season WR mean target share, evaluated separately per window.",
    "Observed-window target share without shrinkage, evaluated per window."
  ],
  "metrics": [
    "Held-out MAE in percentage points per observation window.",
    "Paired improvement over the prior-season baseline per window (percentage points).",
    "95% player-cluster bootstrap intervals for MAE and for paired improvement per window (1000 replicates, seed 271828)."
  ],
  "uncertainty": "1000 player-cluster bootstrap replicates with fixed seed 271828; resampling clusters by player. Intervals are reported for mean absolute error (uncertainty in average error) and for paired improvement per window. These intervals are never presented as individual-player prediction intervals; the article must state the distinction explicitly.",
  "sensitivities": [
    "Common-cohort sensitivity: restrict to players eligible under every observation window, recomputed per window, because eligibility changes with window length.",
    "Team-change sensitivity: identify team changes by the player's dated games for other teams during the outcome interval (not by matching old team game IDs); recompute per window.",
    "Low-team-target sensitivity: threshold of 20 team targets per observed game; recompute per window.",
    "Precision-target sensitivity: operational thresholds of MAE <= 6 pp and improvement >= 0.5 pp over the prior-season baseline, with sensitivity at 4 pp and 8 pp. These are editorial tolerances, not universal statistical thresholds.",
    "Per-season sensitivity: results reported separately for each of the final two completed seasons."
  ],
  "withhold_if": [
    "Fewer than 100 eligible player-window observations for any reported window.",
    "Feature and outcome windows cannot be made strictly disjoint for a player-window (that observation is dropped and the drop is reported).",
    "The full error curve cannot be produced for all six windows; the article must show the curve even if no window meets the operational precision target, and a supported negative finding is publishable.",
    "Insufficient evidence must not be converted into a universal game-count rule; claims about historical forecast reliability must remain distinct from untested 2026 player recommendations."
  ],
  "locked_at": "2026-09-04T11:19:04.013994+00:00"
}