"The outcome is a foregone conclusion," Gates said wryly as a chessboard was brought onto the show.
Carlsen later admitted that he had violated one of his own principle, and used a cheap trick to tope the Microsoft founder.
"He was a bit unlucky and eventually fell to my tactics, but he otherwise made good healthy moves," Carlsen said. "I think with a little more time, he could certainly be a pretty good player."
Gates rushed to the show's London studio by helicopter after a his flight from New York was delayed.