• 25.7 baseline — 0.6 × season 24.9 (20 gm) + 0.4 × last 10 26.8
• −0.8 opponent leak — they concede 357.8/game vs a 369 league average
• +0.9 at this ground — averages 26.6 there (90 gm)
• vs them: averages 27.4 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 2: 39 — far outside his usual range; kept in the average, not smoothed away.