• 4.1 baseline — 0.6 × season 4.1 (20 gm) + 0.4 × last 10 4.0
• +0.2 opponent leak — they concede 34.4/game vs a 32.7 league average
• −0.1 at this ground — averages 4 there (4 gm)
• vs them: averages 3.9 over 7 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 8: 12 — far outside his usual range; kept in the average, not smoothed away.