• 53.8 baseline — 0.6 × season 57.5 (4 gm) + 0.4 × last 10 48.2
• −4.6 opponent leak — they concede 1543/game vs a 1687.8 league average
• at this ground: too thin to count (2 gm) — shown, adds nothing
• vs them: averages 39.7 over 3 games — evidence, never summed

Derived, not measured — plain arithmetic over his real games, shown in full. Adjustments can overlap (a game at this ground can also be a wet one); they add simply, and this note is the admission. Round 16: 133 — far outside his usual range; kept in the average, not smoothed away.