Hey Ray,
I'm sorry to hear that you are having an issue playing videos on the Yahoo! Sports site. I want to suggest clearing your browser's cookies and cache to see whether that resolves your issue. Check out this Help article, which explains how to do this if you haven't done it before:
How to clear your browser's cache and cookies
If that doesn't resolve your issue, you may find some of the information in this Help article useful as well:
News video not working
If either of these articles proves helpful, or ultimately solves your issue, please be sure to mark this reply as such so others know if they experience the same issue, to try these steps.
Please reply to this thread with any other questions.