Secretariat is a movie that gets the seal of approval, very nicely written and shot beautifully. Much of the credit goes to the movie's writer, Rich Mike, who brought plenty of depth and warmth to the movie and its characters, especially Big Red (playing Secretariat) and Tweedy Penny Chenery (played by Diane Lane). Even though people know the story behind the movie and they know how it will end, the storytelling is creative enough to make it worth their while.
The performance given by Diane Lane in this movie is superb, as she plays the housewife which becomes the owner of the Secretariat racehorse. The name of her character is Tweedy Penny Chenery and much of the movie is designed to showcase the relationships between Penny and other characters. These relationships are emotional and strong and they will probably keep the interest of the audience engaged. One example is Jack, Penny's husband, who supports her all the time, even though he doesn't agree with her decision of keeping the horse.
The other one to have relationships in the movie is the horse called Secretariat. His relations with the jockey (played by Otto Thorwarth) and with the trainer (played by John Malkovich) are well developed, though the most special one is with the groom played by Ellis Nelsan. Actually, the movie is mostly based on a book written about the life of Eddie Sweat, which was the groom of Secretariat.
All in all, I think the movie Secretariat is worth the time and money you need to invest in order to see it.