Maybe not pin to PAP is meant, but rather pin to CG distance? Might be outdated lingo these days, though. "Long pin" typically refers to a bigger distance (3"+), and there are "short pins", too. By chosing a proper pin distance for a ball to drill up you can mildly support the general layout (defined by the pin to PAP placement). Low pin balls tend to have a smoother, earlier reaction, while long pins tend to go longer and have a more pronounced breakpoint. The impact is AFAIK minor, though - but when you have the pkan to set up an early-rolling, smooth ball for long oil, a low pin OOB ball might be a good idea for the "overall setup package".