Trends I agree about bias. Much is explainable. Much of the rest is coincidence. One notable exception was the old Aqueduct Inner Dirt... inside was for real.
For trainers, fertile for looks is how a trainer performs early meet, mid-meet, late meet. And, where the horse came in from because that might be a change of assistant trainers.
There are a lot of possible trainer and jockey studies, but sometimes you have to think outside the box.