• 13.1 baseline — 0.6 × season 11.9 (14 gm) + 0.4 × last 10 15.0
• −0.7 opponent leak — they concede 514.9/game vs a 544.6 league average
• at this ground: too thin to count (1 gm) — shown, adds nothing
• +5.5 wet forecast — averages 18.6 in the wet (8 gm)
• vs them: averages 26.5 over 6 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 11: 36 — far outside his usual range; kept in the average, not smoothed away.