I tend to disagree. I do think that the accuracy is related to the number of sensors. I agree that the number of sensors is not the only factor. Certainly the quality of the sensors, the spacing and setup of the sensors are important as well as the type. I think shadow based sensors are more accurate than reflective technology.

With respect to cameras, it purely depends on what you are measuring. To measure direction for ball tracking then the frame rate is way more important than the resolution. In that situation the detail of the balk is not needed. You simply want to know what he direction is so a simple ball steak will suffice. To measur spin however will require much more resolution as well as a fast frame ate and fast shutter speed.