Why??

[Mark Dexter]

I'd hazard a guess that at least 50% of the rules are written exactly the same (perhaps different numbering), and 75-80% of the rules have basically the same intent/underlying philosophy (travelling, 3 seconds, backcourt, the like are the same under both rules).

Where the difference comes is mainly in administrative rules. POI for technicals in NCAA, division line, size of the court, to whom an indirect technical is assessed, where everyone can stand on FT's, number and length of timeouts, etc.

Granted, different places have different philosophies on what to call and when (defender drawing a PC under the basket comes to mind), but what the written rule is doesn't vary a whole lot. If you want to learn them - there's a handy table in the NF and NCAA book giving all the important differences. There are definately fewer differences in basketball than in football!