• 21.6 baseline — his last 10 games; only 2 this season, too few to blend
• −2.1 opponent leak — they concede 1519.7/game vs a 1686.6 league average
• at this ground: too thin to count (2 gm) — shown, adds nothing
• vs them: averages 38.0 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.