As of 2021, which horse does the World Thoroughbred Racehorse Rankings rate as the best racehorse?

Uh, when Secretariat doesn't make even the top three the ranking criteria is garbage.

Very questionable answer and very likely incorrect. Could not find any source for this.

scott, it's not difficult nor garbage; Secretairiat was racing before the establishment of the ranking system referred to.

scott, I agree with you completely!!!