• 0.8 baseline — 0.6 × season 0.7 (11 gm) + 0.4 × last 10 0.8
• −0.0 opponent leak — they concede 31.4/game vs a 32.7 league average
• +0.4 at this ground — averages 1.2 there (28 gm)
• vs them: averages 1.3 over 6 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 23: 4 — far outside his usual range; kept in the average, not smoothed away.