• 21.7 baseline — 0.6 × season 20.3 (7 gm) + 0.4 × last 10 23.9
• −2.2 opponent leak — they concede 1519.7/game vs a 1686.6 league average
• +6.9 at this ground — averages 28.7 there (6 gm)
• vs them: averages 48.0 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 26: 97 — far outside his usual range; kept in the average, not smoothed away.