• 4.2 baseline — 0.6 × season 4.1 (8 gm) + 0.4 × last 10 4.3
• +0.2 opponent leak — they concede 225.5/game vs a 213.6 league average
• −0.6 at this ground — averages 3.6 there (8 gm)
• vs them: averages 6.0 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 11: 9 — far outside his usual range; kept in the average, not smoothed away.