• 1.8 baseline — 0.6 × season 1.9 (7 gm) + 0.4 × last 10 1.6
• −0.0 opponent leak — they concede 35.2/game vs a 35.7 league average
• −0.1 at this ground — averages 1.6 there (8 gm)
• vs them: averages 3.0 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. Round 20: 4 — far outside his usual range; kept in the average, not smoothed away.