• 2.5 baseline — 0.6 × season 2.6 (20 gm) + 0.4 × last 10 2.2
• +0.2 opponent leak — they concede 100.5/game vs a 93.4 league average
• +0.2 at this ground — averages 2.6 there (85 gm)
• vs them: averages 3.9 over 8 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 15: 7 — far outside his usual range; kept in the average, not smoothed away.