There are two components to Sports Bench — a plugin and a theme. Both of them work together and separately. They are written in a way that makes them work the best for you. So if you just need the functionality side of things to go along with a theme you already have, you can get the plugin. Or if you just like the style, you can get the theme. And if you want the easiest solution, you can get them both so that you can have your site up and running in no time at all.
The choice is yours.