when creating a chess.com account you can choose 4 options new to Chess beginner, intermediate, and advanced. The first option gives you a starting elo of 400. The second one gives you 800 the third one gives you 1200 and the fourth one gives you 1600. If 1600 is the highest elo you can start with it’s totally possible for someone that’s rated 2000 to create a new account and start out as a 1600 and win a bunch of games.