from 12.0 baseline, +0.5 at this ground

• 12.0 baseline — 0.6 × season 11.9 (15 gm) + 0.4 × last 10 12.1
• −0.2 opponent leak — they concede 361.8/game vs a 368.4 league average
• +0.5 at this ground — averages 14.1 there against his own 13.4 in those same seasons — 104% of his own level (32 gm)
• vs them: averages 11.1 over 8 games — 97% of his own level in those seasons — 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.