• 2.2 baseline — 0.6 × season 1.2 (5 gm) + 0.4 × last 10 3.6
• −0.0 opponent leak — they concede 185.2/game vs a 185.9 league average
• at this ground: too thin to count (3 gm) — shown, adds nothing
• +7.2 wet forecast — averages 9.4 in the wet (8 gm)
• vs them: averages 8.3 over 7 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 21: 13 — far outside his usual range; kept in the average, not smoothed away.