• 31.7 baseline — 0.6 × season 31.6 (20 gm) + 0.4 × last 10 31.8
• +2.1 opponent leak — they concede 37.6/game vs a 35.3 league average
• +0.0 at this ground — averages 31.7 there (11 gm)
• vs them: averages 33.0 over 1 game — 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 13: 51 — far outside his usual range; kept in the average, not smoothed away.