Heyyo,
Also, if you're using statsme, just delete the 'statsme.log' and blam! stats logging reset. So if a kid starts playing under your username, you can get rid of those horrible stats they put on you.
sv_restart forces the server to reload the map after a few seconds, which resets the ingame stats recording, sv_restartround just restarts the round, but I don't think it resets the ingame stats recording...