• 3.7 baseline — 0.6 × season 3.7 (19 gm) + 0.4 × last 10 3.8
• −0.6 opponent leak — they concede 19.7/game vs a 23.6 league average
• at this ground: too thin to count (3 gm) — shown, adds nothing
• vs them: averages 7.3 over 9 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 20: 16 — far outside his usual range; kept in the average, not smoothed away.