• 0.6 baseline — 0.6 × season 0.6 (12 gm) + 0.4 × last 10 0.7
• −0.0 opponent leak — they concede 4.8/game vs a 5.1 league average
• −0.1 at this ground — averages 0.6 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.