• 4.4 baseline — 0.6 × season 4.4 (11 gm) + 0.4 × last 10 4.5
• +0.6 opponent leak — they concede 106.2/game vs a 93.4 league average
• −0.6 at this ground — averages 3.8 there (42 gm)
• vs them: averages 3.0 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 2: 10 — far outside his usual range; kept in the average, not smoothed away.