• 3.0 baseline — 0.6 × season 2.7 (19 gm) + 0.4 × last 10 3.3
• +0.0 opponent leak — they concede 57.5/game vs a 56.6 league average
• −0.9 at this ground — averages 2.1 there (32 gm)
• vs them: averages 3.5 over 2 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 19: 8 — far outside his usual range; kept in the average, not smoothed away.