I think that you need to narrow your topic (which sport ? to find or do what ? meet which user need ?), however I'm now convinced that you can make something out of it.
Just sharing, I was last week at the NRF in New-York, the retail event of the year. I attended a session where speakernotes from major leagues were on stage to share how they use data to engage with the fans. Just imagine, on stage : International Tennis League, NBA, German Soccer Rep, NHL, and US Football, ie $$$! The discussion and sharing were below any expectation. They just don't know how to use data, how to engage with users, they only use them to give you a seat and basically sell you more bear, more food. They predict sports for professionals, nothing for the fans.
You have a need to meet, no mass market social media like Facebook do it in a way that is engaging on sports experience, like suspens, enthusiasm, self-esteem, passion that triggers sports with fans.
So maybe, try to see if a sport league, even local, would partner with you, to really allow you to further work on your project and find what the others did not find.
Timing is good, mass social media are mature, they have a huge reach anf fight for retention of active users against ads push selling. Social Media segmentation per target / needs / innovative experience is just starting. It will not be easy, but what is easy when you build a start-up, let's be honest : nothing. If we do not accept that, just not start, there are easier jobs, really.