• 2.9 baseline — 0.6 × season 3.6 (5 gm) + 0.4 × last 10 1.9
• +0.2 opponent leak — they concede 38.4/game vs a 35.7 league average
• −1.0 at this ground — averages 1.9 there (17 gm)
• vs them: averages 1.0 over 1 game — 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 6: 8 — far outside his usual range; kept in the average, not smoothed away.