• 8.7 baseline — his last 10 games; only 3 this season, too few to blend
• −0.2 opponent leak — they concede 209.2/game vs a 213.6 league average
• −0.2 at this ground — averages 8.5 there (8 gm)
• vs them: averages 8.7 over 3 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 19: 14 — far outside his usual range; kept in the average, not smoothed away.