• 0.8 baseline — 0.6 × season 0.8 (17 gm) + 0.4 × last 10 0.8
• +0.0 opponent leak — they concede 9.8/game vs a 9.7 league average
• at this ground: too thin to count (1 gm) — shown, adds nothing
• +0.4 wet forecast — averages 1.2 in the wet (9 gm)
• vs them: averages 1.0 over 10 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 8: 4 — far outside his usual range; kept in the average, not smoothed away.