I would imagine the type of fouling has to be followed through.
Crappy perimeter defenders will probably pick up fouls on perimeter shots. Crappy inside defenders - on inside shots. Crappy shotblockers - probably on both, though I suspect this skill might be used a bit more often for inside shots.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."