I didn't say it was fool proof. But its part of experience. When stats were first being developed they were not anywhere as accurate as they are now, or will be in the future. I'll give you an example, in my younger years, I owned, raced and gambled on greyhounds.
I was pretty good at it. What I found was that to be somewhat successful you needed an edge. Meaning the more quality information I could obtain the better I was. Most people would buy the racing program and attempt to "handicap" from there. What I found was that the comments in the program were not always accurate, also that the track conditions, health of the kennel, post position, my experience, grade of the dog, and odds would all have an effect on the outcome. I did much better than the average bettor. The same is somwhat true withregards to prospects vs vetererns. I've just seen way to many projected studs not make it. On the other hand, maybe I just want to go with more or a sure thing because I don't have a lot of years left to waste.