Sven Magnus Øen Carlsen is a Norwegian chess superstar. He is not only the current World Chess Champion but he has achieved the highest rating ever by a human being in Chess. That makes him the best player ever by the measurement we call the Elo rating system.
It is hard to convey how good Magnus Carlsen is at chess to people who may be new to the game but imagine a singer like a world class singer like Justin Beiber or Kanye West, then imagine another singer who makes them sound like they are singing off key. It is as if there are levels of genius and he is a the top above mere genius.
A professional grandmaster can have an Elo rating of above 2500, Magnus Carlsen has a rating of 2840 and often much above that. This dominance is staggering since professional grandmasters are working a near genius level at chess and yet are like beginners when they play Magnus Carlsen.
Chess is played at different speeds and Magnus Carlsen is master of all of them. He famously won all World Championship title in all classical formats of Chess, (Classic, Rapid and Blitz).
After all is said and done Magnus Carlsen is a phenomenon, a Chess Thor.