From the TSSAA Bylaws:
Article II
Section 13 E:
If a student with an athletic record transfers to a new school where an “athletic coaching link” existed in the past 12 months, that student is ineligible for 12 months past their first date of enrollment at the new school at all levels in the specific sports where a linkage was present. Links may include (1) attendance at an individual camp (and then transferring); (2) playing on non-school (independent) teams (and then transferring to that coach’s school); (3) transferring into a school where a former coach has been hired; and (4) transferring to a school where a former or current personal trainer or strength and conditioning coach is employed.
This is easy to prove. The kid played at Raleigh Egypt last year, the coach was the head coach at Raleigh Egypt.