Do they factor age or is that just rankings based on ability?
Never had a definitive answer to that. Been told it is all scores, all ages, reported into Nike...which owns the SPARQ trademark.
My unscientific experience is that 65 is noteworthy for a high schooler seeking to play D1, and 70 is something you can legitimately brag about. (For pitchers it is not always relevant, same for prodigious power hitters) Stanford Camp does SPARQ testing and they give you your rank compared to other players at the camp.