Are you interested in simulating what-if games for sports or simulated leagues with almost all players from baseball, American football, and basketball history? Then check out www.whatifsports.com
DISCLAIMER:
I am not the people who run this site and I am not responsible for any of its content, I find the pay leagues it has disturbing personally, but no one else offers this.

I meant "Is this site worth visiting" for the poll.

Not really as it doesn't include Football ;)