Are we talking one-off performances or like one-day performances? I was impressed with German's 1600/3200 double at California State Meet. Didn't he run like 4:00 and 8:39 within like two hours of each other? (Not sure of exact times but I think I'm close?). That to me is the greatest high school only performance of all time...
There are really 5 categories.
HS athletes competing in their state’s sanctioned competitions. German’s double and Ryun’s sub-4 at their state meets meet fall into this category.
Events for high school only competitors that are not NFHS sanctioned, such as the post-season XC and track meets.
Events where athletes still HS eligible compete against pro athletes. Webb’s 3:53, Colin’s 3:58, etc.
Athletes that are still in HS but have signed pro contracts and compete as pros. Knighton, Cain, etc.
A final category would for athletes competing when only amateurs were eligible for Olympic competition. Mathias and Ryun competed against the best in the world as high schoolers but they were not technically competing against pros.
Wow, and there is a thread whining about 3 running categories being too many. You came up with ten just for runners who are in high school.