I’ve added a place on the player pages where you can leave a comment or have a threaded discussion about a particular player. You can log in using pretty much whichever service you want (twitter, facebook, google, etc…), or continue to comment anonymously.
We tried something like this a couple years ago for a short amount of time and it didn’t work out too well, but I think it’s worth trying again.
The comments section is at the very bottom of the page (with a link at the top of the page showing how many comments there are) so it doesn’t get in the way of your stats browsing.
David Appelman is the creator of FanGraphs.