• 10.4 baseline — 0.6 × season 10.8 (8 gm) + 0.4 × last 10 9.9
• +0.3 opponent leak — they concede 378.4/game vs a 369 league average
• +0.4 at this ground — averages 10.8 there (30 gm)
• vs them: averages 10.0 over 6 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 17: 0 — far outside his usual range; kept in the average, not smoothed away.