• 11.3 baseline — 0.6 × season 11.1 (13 gm) + 0.4 × last 10 11.7
• −0.3 opponent leak — they concede 360.2/game vs a 369 league average
• +3.3 at this ground — averages 14.6 there (17 gm)
• vs them: averages 22.5 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 6: 19 — far outside his usual range; kept in the average, not smoothed away.