• 5.7 baseline — 0.6 × season 5.7 (14 gm) + 0.4 × last 10 5.6
• −0.2 opponent leak — they concede 207.8/game vs a 213.6 league average
• +1.1 at this ground — averages 6.8 there (70 gm)
• vs them: averages 7.3 over 7 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 18: 11 — far outside his usual range; kept in the average, not smoothed away.