Who are the known dupes?

Aside from those who cheat in other ways, who are known to be duplicate active accounts for the same human but not known to use computers or MiM?

It was reported long ago that Horst Dog (the recent winner of the chess championship) is the same person as iwan. Can someone say how this is known? Assuming it's true, this person is taking up two spots in the championship structure, where one spot should be available to another player.

Does the same apply to joerg and jot?

I have no idea if the players you mention are the same person, but I want to point out that the problem is bigger than simply taking out spots in the championship. Two or more aliases of the same player can easily manipulate the final result of a championship or a tournament. This is, by the way, what the resident cheater used to do: the games between his aliases were always the last to finish so he would know which alias needed to get the points needed to win the championship or the tournament.

Definition of dupe from dictionary.com

1.

a person who is easily deceived or fooled; gull.

2.

a person who unquestioningly or unwittingly serves a cause or another person: a dupe of the opponents.

From urbandictionary.com

dupe

1. n. A duplicate

(rarely) v. To duplicate something

2. To deliberately confuse or scam someone

1. n.: There are too many dupes on UD.

\* v.: The idiot was bored so he duped someone else's definition and added some offensive words.