• 3.2 baseline — 0.6 × season 3.4 (16 gm) + 0.4 × last 10 3.0
• +0.2 opponent leak — they concede 38.4/game vs a 35.7 league average
• −1.1 at this ground — averages 2.2 there (18 gm)
• vs them: averages 3.0 over 2 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 18: 10 — far outside his usual range; kept in the average, not smoothed away.