• 3.1 baseline — 0.6 × season 3.1 (9 gm) + 0.4 × last 10 3.2
• −0.4 opponent leak — they concede 49/game vs a 56.6 league average
• −0.5 at this ground — averages 2.6 there (34 gm)
• vs them: averages 4.3 over 3 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 14: 8 — far outside his usual range; kept in the average, not smoothed away.