• 12.8 baseline — 0.6 × season 13.7 (6 gm) + 0.4 × last 10 11.5
• −0.4 opponent leak — they concede 357.8/game vs a 369 league average
• vs them: averages 10.0 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 7: 24 — far outside his usual range; kept in the average, not smoothed away.