• 1.5 baseline — 0.6 × season 1.8 (18 gm) + 0.4 × last 10 1.2
• −0.1 opponent leak — they concede 22.1/game vs a 23.7 league average
• −0.6 at this ground — averages 1 there (25 gm)
• vs them: averages 2.4 over 5 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 8: 12 — far outside his usual range; kept in the average, not smoothed away.