• 11.6 baseline — 0.6 × season 11.9 (7 gm) + 0.4 × last 10 11.2
• +0.5 opponent leak — they concede 386.2/game vs a 369 league average
• −1.0 at this ground — averages 10.6 there (9 gm)
• vs them: averages 8.0 over 2 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 4: 19 — far outside his usual range; kept in the average, not smoothed away.