How Carlsen’s Blunder To Duda Ended An Amazing Unbeaten Streak
In the endgame before Carlsen resigns, he stares at his losing position. Duda has just moved 62.Qh7+. Photo: Lennart Ootes/Norway Chess.

How Carlsen’s Blunder To Duda Ended An Amazing Unbeaten Streak


The most fascinating game of 2020 is the standard game between World Champion GM Magnus Carlsen and GM Jan-Krzysztof Duda (world number-15) in the Altibox Norway Chess tournament. Carlsen lost!

Carlsen at Altibox Norway Chess
Carlsen confidently makes a move early in the game. Photo: Lennart Ootes/Norway Chess.

This game may rank among the most surprising outcomes in chess of all time. The loss was Carlsen’s first defeat in more than two years, and it occurred in his native Norway. The game, the blunder, the streak, and the tournament are now part of the significant lore of chess, and the reflections by both players help to put the outcome in perspective.

Duda at Altibox Norway Chess
Duda looks up as he awaits Carlsen's next move. Photo: Lennart Ootes/Norway Chess.

The Game

The game was played in the fifth round of the 8th Altibox Norway Chess tournament on Saturday, October 10, 2020. After playing an unusual variation of the Caro-Kann in the opening, Carlsen chose to exchange a rook for a bishop to open the b-file file to set up the potential for an aggressive attack on White’s king. However, with 21…h4, Carlsen allowed Duda to consolidate his position in the next few moves. The board below is set after White's 31st move.

The Blunder

About Carlsen’s move 31…Qxa2, Duda said: “He obviously blundered” because the Polish GM was able to defend his king by moving his queen to c2 and then capture Carlsen’s remaining rook on the back rank with 33.Re8+. (Why Carlsen cannot capture with 33…Rxe8 is explained in the tournament report—see the link below—and is worth taking the time to review.)

Carlsen's queen before capturing the a2-pawn.
Carlsen's queen sits on g2 before it captures the a2-pawn. Photo: Lennart Ootes/Norway Chess.

Carlsen continued to play a rook and exchange down, but the material imbalance was too severe. Carlsen resigned after Duda’s 63rd move. Because the purpose of this post is not to analyze the game itself but to examine the significance of the loss, I instead refer you to comprehensive analyses about the game by experts:

Duda's rook checks Carlsen's king
Duda has just played 33.Re8+. The body language of each player tells that the outcome of the game can be anticipated. Photo: Lennart Ootes/Norway Chess.

The Streak

The loss was Carlsen’s first one since July 31, 2018, when he lost to Azerbaijani GM Shakhriyar Mamedyarov at the Biel Chess Festival. The unbeaten streak, when Carlsen scored 42 wins and 83 draws, is a significant record. It lasted for two years, two months, and 10 days and extended for 125 classical games. How long will it stand?

Carlsen and Duda at Altibox Norway Chess
With both rooks now off the board, Carlsen realizes that his options are limited. Lennart Ootes/Norway Chess.

The Tournament

The tournament began on October 5, 2020 in Stavanger, Norway, and ended on October 16. It was a double round-robin with six players—the other four were GMs Levon Aronian, Fabiano Caruana, Alireza Firouzja, and Aryan Tari. The time control for each standard game was two hours for all moves with a 10-second increment per move after move 40. (The tournament also included an armageddon game if a standard game ended in a draw.)

Round 5 of Altibox Norway Chess
The three games of Round 5 are underway. Photo: Lennart Ootes/Norway Chess. Chess

The Reflections

After ending Carlsen's 125-game unbeaten streak, Duda commented: "I'm very happy, obviously! I didn't expect to win this game at all…. I almost blundered checkmate in one move."

A day after the loss, Carlsen and Duda had a rematch that the world champion won. After his win, Carlsen reflected on his loss in the previous game and the end of his unbeaten streak:

Losing wasn’t that big a deal, like a hundred games and then the record streak. Those were the ones that I really cared about. And after that, I knew that I was going to lose at some point, and especially I was taking risks in my games. But anyway, losing a poor game yesterday is obviously unpleasant no matter what’s at stake. I was mostly upset at losing in general, not so much the streak. But at least now there is no streak, so I don’t have to worry about that.

Now it's your turn. Are you amazed by Carlsen's unbeaten streak? How long do you think it will last?