• 2.5 baseline — 0.6 × season 2.5 (12 gm) + 0.4 × last 10 2.4
• −0.0 opponent leak — they concede 55.5/game vs a 56.6 league average
• −0.7 at this ground — averages 1.7 there (50 gm)
• vs them: averages 1.8 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 17: 6 — far outside his usual range; kept in the average, not smoothed away.