Originally posted by kkenji
I've often wondered about this kind of thing myself. How site admins determine whether it's a case of 2 people sharing 1 IP or 1 computer, or 1 person having 2 accounts. Perhaps as an extra precaution you should also avoid playing against your wife. This has the added benefit of preserving domestic harmony.
You certainly don't want a bunch of games with one player losing to fools or scholar's mate every time.
You also don't want to run around the forum constantly agreeing with the user on the same IP, this makes it look like the same person.
One Pro Tip
for avoiding posting or playing chess moves from the same IP on the WRONG user name is the two players use two different chess sites.
One logs in at Redhotpawn or Playtheimmortal game while the other logs in at Timeforchess or chessatwork. That way when one sits down they can see instantly by color that they are logged in with the wrong name rather than posting or moving pieces under the other user's name.