• 12.9 baseline — 0.6 × season 13.7 (6 gm) + 0.4 × last 10 11.7
• +0.7 opponent leak — they concede 164/game vs a 155.4 league average
• wet forecast: too thin to count (2 gm) — shown, adds nothing

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 12: 3 — far outside his usual range; kept in the average, not smoothed away.