Magnus Carlsen's game at the World Fishermen's Chess Championship in Reykjavik was a constant ups and downs. At one point he forgot his planned move and instead made what he intended to do next.

In this case, it cost him a rook, and possible victory turned into certain defeat.

Doing the second before the first is called this type of mistake when the thoughts have already rushed ahead.

If Carlsen doesn't have a head for chess at the moment, that's understandable.

Hans Niemann, the young American he suspects of fraud, has filed a lawsuit seeking $100 million in damages from him and others for damage to his reputation.

That's more than the 31-year-old world champion has earned in online chess in the form of fees, prize money, advertising income and company investments.

His New York lawyer Craig Reiser has rejected the claim as unfounded.

But Carlsen's moves reveal that she's keeping him busy.

Especially when he loses four times in a row.

Carlsen demands speed

It happened in the semifinals against Jan Nepomnyashchi, whom he outclassed 7.5:3.5 at the 2021 World Classical Chess Championship in Dubai.

Carlsen won the first of their four games in Reykjavik, only to be countered twice in a row by the Russian.

Carlsen lost the next encounter because he absolutely had to win it to even the score.

The following day, his match for third place against the talented Uzbek Nodirbek Abdusattorov also started in defeat as he persisted in playing for a win rather than settling for a draw when his advantage had evaporated.

Then Carlsen got the curve, won the remaining games and was at least third.

Nepomnjaschtschi lost the final against Hikaru Nakamura, who played the most balanced game of all eight participants and, in addition to his first world championship title, secured 150,000 euros in prize money.

Matthias Blübaum from Lemgo finished seventh, just one place behind Wesley So, who won the first World Chess Championship for Fishermen recognized by the World Chess Federation FIDE in 2019.

The basic line-up in Fischerschach is not predetermined, but drawn by lot.

The tournament in Iceland commemorated their inventor Bobby Fischer, who became world champion in Reykjavik in 1972, received political asylum there in 2005 and died as an Icelandic citizen in 2009.

Instead of being able to follow umpteen practiced and rehearsed variations, the players are on their own from the very first move.

Concentration and form on the day are even more important than in classic chess.

Carlsen thinks it is wrong that Fischer chess competitions are organized almost exclusively in rapid chess mode.

It should also be offered with a long reflection period, he told Icelandic television.

Conversely, classical chess must become faster so that more mistakes are made and draws are not played as often at the highest level.

He has just confirmed in writing to FIDE that he will not defend his title in classical chess in 2023.

In his place, Chinese Ding Liren will take on Candidates Tournament winner Nepomnyashchi.

Carlsen told the Norwegian broadcaster NRK that he could well imagine a comeback if the pace of play at the World Championships in classical chess was one day accelerated.

However, he turned down an invitation to a world-class tournament in Düsseldorf in February.

Perhaps because neither Fischer's chess is played there, nor is it played with a shorter time control.