ilyazhito wrote ... curious why a ball passing over a fan-shaped backboard is not out of bounds under NFHS rules.
It's a simple matter of geometry.
A rectangular backboard has well defined upper corners that separate the top from the sides.
A fan shaped backboard, while having well defined sides near the bottom, has poorly defined curved "corners" closer to the top, where one needs to consider tangents.
Of course, once one starts to consider tangents, one needs to whip out one's trusty trigonometry slide rule.
Mark T. DeNucci, Sr., as an engineer, can expound upon this when he gets back from his tropical cruise.
