Can anyone tell me, or refer me to a book, on how to determine if a horse has ran against stiff competition.?

Question

I'm not talking about other race classes. About odds, Beyers etc.

Answer 1

Races are rated by classes,  the highest class would be a graded stakes race, then there is just a stakes race. You have allowances,  optional claimers,  and last would be claiming races the lower the claiming price usually the slower the competition.  You can see past performances on equibase or you can refer to past race programs. I hope this helps you.

Answer 2

If your referring to North American racing you may want to refer to the Daily Racing Forms American Racing Manual. It is published annually and summarizes all major North American stake races, individual meets at different tracks and so on, I think it's about 1000 pages of every horse racing stat you can think of for North America.