• 11.1 baseline — 0.6 × season 11.3 (9 gm) + 0.4 × last 10 10.8
• −0.1 opponent leak — they concede 364.1/game vs a 369 league average
• −1.0 at this ground — averages 10.1 there (44 gm)
• vs them: averages 10.0 over 4 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: 18 — far outside his usual range; kept in the average, not smoothed away.