It's funny... American Pharaoh will go down in history as a great horse, and there's no doubt that winning the Triple Crown is an amazing accomplishment. However, his Kentucky Derby time was slow compared to other winners, and his Preakness winning time was the worst in over 50 years. He did run the Belmont exceptionally fast, but most years he wouldn't have won either of the first two races.
So, is he a great horse, or did he just run against historically weak fields? It's no doubt an awesome accomplishment, but I have a hard time saying that AP is a better horse than, say, Smarty Jones.