• 3.9 baseline — 0.6 × season 3.9 (8 gm) + 0.4 × last 8 3.9
• −0.0 opponent leak — they concede 211.7/game vs a 213.6 league average

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: 0 — far outside his usual range; kept in the average, not smoothed away.