I have a friend who had 500+ points in bullet and rapid rooms, but he played the last chess tournament and won all his games. So yesterday he plays a normal game and suddenly he has the program sign in all the rooms. How is the possible? Does the system just assume you are a cheater because you win all the games?

He is a fair player and has played many tournaments and finished in a good position many times. I think we need moderators who really know about chess and observe the games.I would like to know how the system detects cheaters in a tournament.