• 1.0 baseline — 0.6 × season 1.2 (6 gm) + 0.4 × last 9 0.8
• +0.1 opponent leak — they concede 38.4/game vs a 35.7 league average
• at this ground: 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 21: 4 — far outside his usual range; kept in the average, not smoothed away.