• 2.5 baseline — 0.6 × season 2.4 (17 gm) + 0.4 × last 10 2.6
• −0.5 opponent leak — they concede 26.6/game vs a 32.7 league average
• −0.3 at this ground — averages 2.2 there (20 gm)
• vs them: averages 2.5 over 8 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 10: 7 — far outside his usual range; kept in the average, not smoothed away.