I just saw this tonight and I LOVED it!!!!!!
As to the beginning of the movie, it is a little choppy if you don't know the history. I saw a documentary on it just a couple days ago, and that made a world of difference understanding the movie better. For those that haven't seen it yet, it goes through the background of the 3 principle people involved (the owner, the trainer and the jockey) and how fate brought them together. It goes back and forth on each persons story until it all comes together.
It is sooooooo good! I laughed, I cried, and I felt inspired!