Magnus Carlsen retained his world chess championship title by defeating challenger Ian Nepomniachtchi. The final score was 7.5 to 3.5 in favor of Carlsen. Carlsen won 4 games and lost 0. There were 7 draws.
Nepomniachtchi, age 31, is a Russian Grandmaster who gained the right to challenge Carlsen by winning a Candidates Tournament in 2020.
Carlsen, age 31 from Norway, first won the title in 2013 by defeating then-champion Viswanathan Anand (India). Carlsen successfully defended his title in 2015 (rematch vs. Anand), 2016 (vs. Sergey Karjakin, Russia), and 2018 (vs. Fabiano Caruana, U.S.)
There is a long and fascinating history of the connection between chess and computer science. For me, personally, one of the defining moments of my life occurred in 1973 when I played one of the earliest chess programs on a mainframe computer when I was a student at U.C. Irvine. I can still remember feeling my heart race when the computer clackety-clacked its first move on a teletypewriter machine.
In Game 6, with the match tied 2.5-2.5, Carlsen won the longest game in championship history (136 moves).
Two games later in Game 8, with the match score 4-3, Nepo made a serious mistake that lost a pawn to a relatively simple tactic and Carlsen took a commanding 5-3 lead. See my post at https://jamesmccaffrey.wordpress.com/2014/12/17/my-top-ten-favorite-world-chess-championship-blunders/.
Left: In Game 9, Nepo, playing white, has just played 27.c5 to save the c-pawn which was under attack by Carlsen’s black rook on a4. Carlsen replied with 27… c6 which trapped the Nepos’ white bishop on b7. A few moves later Carlsen won the bishop by attacking it with both his rooks. But the game remained razor-sharp because Nepo pushed his a-pawn down the board and almost converted it to a queen.
Right: In Game 11, Nepo playing white, has just played 23.g3 to attack Carlsen’s black rook on f4. Carlsen sacrificed rook for knight by playing 23… dxe3 and won with an attack that eventually left him a pawn ahead — plenty for a Grandmaster to win the game and retain the title.