genetics role in horse racing

Question
hello sir, may i know how much percent role does a horse genetics (blood line) play in thoroughbred racing? would you say that a horse perform well in the race through its superior pedigree or through excellent training?

Answer
Starting with superior pedigree is definitely a gift to the poor to average trainer. There are excellent trainers that can train a horse well enough to overcome it's mediocre breeding and equal or better, a well bred horse, who has an average trainer. The superbly bred horse's best chance at success is to have a skilled and knowledgeable trainer. Most trainers in America rely on breeding and overlook the power of knowledge. North America is famous for breeding sub par horses to sub par horses. It's quite a challenge for the advanced trainer to make something out of mediocrity. A horse with superior breeding will almost always fail under the wrong management.