Thoughts on: long but descriptive SEO-friendly subtitle or short subtitle

I’m writing a non-fiction narrative about my great great grandpa. He was a colorful character who got into a lot of bloody fights, but was also instrumental in building up early California, particularly professional sports. He lived in Sacramento and then San Francisco as well, but my focus is on what he achieved while in Sacramento. The title would be his name followed by “The Gilt Edge of Ambition in Post Gold-Rush Sacramento”. I think most people who would initially be interested in it would be those interested in early Sacramento history or early sports history in California (his first team was named Gilt Edge). So I was trying to be extra descriptive. But I noticed, for example, the subtitle of Seabiscuit is simply An American Legend. Which doesn’t add any extra SEO. Perhaps just “The Gilt Edge of Ambition” or perhaps something entirely different. What are your thoughts?