• 0.8 baseline — 0.6 × season 0.8 (12 gm) + 0.4 × last 10 0.9
• −0.1 opponent leak — they concede 3.6/game vs a 3.9 league average
• −0.6 at this ground — averages 0.3 there (16 gm)
• vs them: averages 0.0 over 1 game — 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: 4 — far outside his usual range; kept in the average, not smoothed away.