"Do We Need a Sturdier Racehorse?"

[Riot]

This doesn't make sense at all to me. The more breeding you do - the better your population should get over time.

That's a measurable quantity, the breeding boom has been looked at, and Chuck's right: If you breed 20,000 horses, and have 10,000 end up "race quality", breeding 35,000 horses doesn't get you any more race quality, it just gets you more crap on the bottom, because it's an increase in breeding lesser-quality animals, not best-quality. Weird but genetically true. Breed more = less quality (unless you go to genetic cloning)