• 0.5 baseline — his last 10 games; only 2 this season, too few to blend
• −0.0 opponent leak — they concede 34.2/game vs a 35.7 league average
• −0.1 at this ground — averages 0.4 there (12 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.