Carlsen’s route to the semifinals was anything but smooth. He started his match against Fabiano Caruana with a loss after a grave mistake. Facing a must-win situation with Black, Carlsen forced tiebreaks, won the first blitz game and closed the match with a second win.

Javokhir Sindarov continued his momentum from the round-robin stage. After Parham Maghsoodloo’s 0/7 in the preliminaries, the Iranian still managed to create a crushing position in game one but let it slip. Sindarov survived, turned the game around and won game two as well, finishing the match 2–0.

Vincent Keymer became the second player to advance. After drawing game one against Arjun Erigaisi, he took over in game two as his opponent blundered an exchange, and converted calmly to reach the semifinals. Levon Aronian later joined him by defeating Hans Niemann. Both players spoiled close to winning positions in the 30+15 games; Aronian finished the job in the tiebreaks.

The semifinal lineup for Wednesday and the pairings in the Lower Bracket:

• Magnus Carlsen vs. Javokhir Sindarov
• Vincent Keymer vs. Levon Aronian
• Fabiano Caruana vs. Parham Maghsoodloo
• Hans Niemann vs. Arjun Erigaisi

Another day, another format, another time control. With the Quarterfinals on the program, the players moved to a Knockout with matches consisting of two 30+15 games, meaning half an hour on the clock but also 15 seconds with each move made. The first position was #305, drawn by Etan Ilfeld, Diving Chess founder and CEO of the Mind Sports Olympiad. As it turned out, the players had different ideas about the best first move.

Keymer made an early visit to the confession booth and said: “I think we had a very complex starting position with many options for both sides.” He called Arjun’s 1.f4 “quite a sharp move,” adding: “It gives me the option to either go for symmetry with 1…f5 or 1…c5 as I did in the game.” He chose the Sicilian kind of position as it had been suggested by Caruana in the joint analysis beforehand.

Arjun himself said: “We were mainly discussing 1.d4 and 1.e4 and in the end someone mentioned 1.b4. At the board when I was thinking, 1.f4 also looked interesting me. I spent some time and I quite liked the lines there.” He further explained that it was his preferred way of reaching a (Grand Prix?) Sicilian kind of position without allowing 1.e4 e5.

Aronian was that “someone” mentioned by Arjun, saying: “I managed to surprise Hans with my 1.b4. We came to this idea right before the game and I think it’s playable. At least it creates imbalance and I feel it will be some sort of a sharp game which is something I look forward to.”

Let’s take it from there, and see how the matches unfolded today.

Carlsen – Caruana 3-1

Considering the Grand Slam Tour standings, where Carlsen had a 31-point lead over Caruana, this matchup was a must-win for the American grandmaster, and he started well. It was also a case of Carlsen starting badly, as he rather uncharacteristically collapsed in just a few moves from a better middlegame position. It should be said that Caruana’s 21…Kh8! was a superb move. The whole tour was suddenly wide open as Carlsen resigned with a wry smile.

“Losing the first of course was a big blow, especially the way that I did: first kind of surviving a difficult position and then just giving it away and having like an absolute brain hemorrhage in just a few moves thinking that I could take his queen when I’m in check,” Carlsen commented later in the day. “I had missed his previous couple of moves as well; it was a complete and utter meltdown.”

That meant that Carlsen had to win with the black pieces, never an easy task but if anyone could do it, it was him. It took a bit before he could start that game, though. “I was really pissed that we had to wait for an hour and a half for the next game but in retrospect it was probably not a bad thing,” said Carlsen.

The second position of the day was in fact position #1, drawn by Diving Chess World Champion Michal Mazurkiewicz. Carlsen maneuvered patiently in this game and waited until Caruana came under the one-minute mark, then set a trap and Caruana fell for it.

Carlsen then won both blitz games, played at the rather fast 5+2 time control. That didn’t go as smoothly as it seemed.

“I did feel very good about being there but it was difficult to adjust to quicker chess,” he said. “I had to tell myself several times, ‘make a move, come one, what are you doing?’ But then my intuition wasn’t really telling me anything because we’re playing Freestyle and it’s more difficult, the pieces are in slightly different squares than I’m used to. But fortunately when it came down to bullet scramble I am usually a bit better than him there, so I managed to pull it out.”

The first blitz game was key as it was once again a win with the black pieces.

After this, it was relatively easy for Carlsen to keep things under control with White in the second blitz game, which was one of the most expensive blitz games in chess history. By winning this one as well, and eliminating Caruana, the Norwegian super GM is now certain of the Grand Slam title and the $100,000 bonus that comes with it.

Aronian – Niemann 3-1

This matchup was a repeat of the Las Vegas final, after it was Aronian’s wife Ani who had picked Niemann as the opponent for her husband. “I would most likely also pick Hans because I think Vincent won in such a manner in Weissenhaus that I have so much respect for him; it’s natural for me to pick Hans,” said Aronian about this.

The American-Armenian grandmaster got a big advantage as White in the first game and commented in the confession booth: “I feel Hans shouldn’t have allowed 7.d5, he should have played something sharp. He played kind of slow and now my position looks almost winning. I have to pay attention not to blunder anything but objectively this looks really good.”

It cannot be called a blunder, but Aronian did allow Niemann back into the game (31…Be3! was a great save) and had to force a draw when that happened.

In the second game it was Niemann’s turn to get a very good position and then to spoil it to a draw.

This match also went to the blitz stage, and Aronian would later call it “brutal” to play Freestyle in a blitz time control: “It feels like bullet because you know blunders are going to come!”

In the first blitz game, Niemann had a winning position at some point:

The second game also saw a wild time scramble:

Sindarov – Maghsoodloo 2-0

In this match, both players continued where they had left it with the round-robin stage: Sindarov once again achieving an impressive result, and poor Maghsoodloo once again losing all his games. The Iranian grandmaster even repeated the scenario of the other day, as he was winning in the very first round then, and also in his first game with Sindarov today.

Commentator David Howell went as far as calling it a “blunder” that Sindarav had chosen to start with the black pieces, and he did get into trouble in the early middlegame. 25…Ng6 could be called a second blunder as it allowed a simple tactic that even an off-form Maghsoodloo found instantly. He then played too fast though, allowed his opponent back in the game, and then he even ended up losing.

Sindarov seemed to be scoring a quick win in the next game when Maghsoodloo played two bad opening moves, but the latter managed to make it a true game after all. Still, it was Sindarov who soon dominated again and won another powerful game. An impressive first two days for the FIDE World Cup winner, who is still undefeated, while Maghsoodloo will need to find his confidence back as he continues his tournament in the Lower Bracket.

Keymer – Arjun 1.5-0.5

A complicated first game ended in a draw after 50 moves, with Keymer being an exchange down but having much more active pieces to fully compensate for it. The second encounter was a much more topsy-turvy affair.

Keymer felt confident out of the opening, saying in the confession booth: “I think we got a quite interesting position as White. Right now I’m quite happy with my position; I think the queen on b8 has issues to get out.”

After poor moves 16 and 17 from Keymer, it was Arjun who completely took over. Afterward, Keymer admitted that he had “messed it up somewhere between a lot and completely.”

The last and biggest mistake, however, came from Arjun, who must have completely missed 25.Bh3 with which he blundered an exchange and the game in one move.

Keymer pointed out that in the whole tour, he had never lost the first match he played in each event, even in Las Vegas, when it was in the Lower Bracket. One thing is certain: everyone will have Weissenhaus in mind and no one will underestimate Keymer.