Niemann's Queen Sacrifice Shakes Up Round 4

Photo: TheBoburshokh / Wikimedia Commons (CC0)

Let us start with a puzzle from the game. It is White to move, in the position below. Niemann found a sacrifice here that wins the game. Can you find it? The answer comes later in this article.

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White to move, after 37...fxg3. Find the move that wins.

Analyze this position in the full game

Hans Niemann 1-0 Abhimanyu Mishra, 2026 U.S. Championship, Saint Louis, Round 4, 12 October 2026.

The round in one line

Round 4 of the Open section had four decisive games. Niemann beat Mishra with a queen sacrifice, Jeffery Xiong beat co-leader Awonder Liang, Grigoriy Oparin beat Sam Sevian, and defending champion Fabiano Caruana beat Ray Robson. Wesley So drew Levon Aronian. So and Caruana now share the lead on 3 points.

A quiet opening, then a pawn

The game opened 1.Nf3 d5 2.d4 Nf6 3.c4 c6. Niemann started with the knight, developing a piece before pushing a center pawn. Mishra answered solidly, and for the first 25 moves the game stayed close to level. This was maneuvering chess, both players improving their pieces one square at a time.

The first real damage came on move 26. Niemann played 26.Nxb7, snatching a pawn deep in Black's territory. A few moves later the knights came off and Mishra captured on b7 with 29...Rxb7, but White kept the extra pawn. On the queenside White now had three pawns (a2, b3, d4) against Black's two (a7, c6). Three pawns against two tend to produce a passed pawn sooner or later.

A passed pawn is a pawn with no enemy pawn ahead of it on its own file or the files next to it. Only pieces can stop it, which means it gets stronger as pieces come off the board. Remember that. It is the whole game.

The pawn that would not stop

On move 30, Niemann pushed 30.d5. Two moves later Mishra played 32...Qg5, and our Stockfish 17.1 run at depth 20 marks it as the move that let White in. Trading queens with 32...Qxg3 was the engine's choice. Instead came 33.dxc6, and there it was: a white pawn on c6, passed, with a clear road to the queening square.

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After 33.dxc6. The c-pawn is passed: Black has no pawn on the b, c or d files to stop it.

Analyze this position in the full game

Black's own pawn ran the other way. Mishra had pushed 30...f4, and on move 37 it captured on g3, right next to White's king. But Niemann had just played 37.c7, putting the c-pawn one step from becoming a queen. There is an old endgame rule that every beginner should know by heart: passed pawns must be pushed.

The sacrifice

Here is the puzzle position again. White to move, pawn on c7, one step from a new queen.

Only one black piece guards the queening square c8: the rook on f8. And the bishop on c5 protects that rook. So White needs to remove both of them.

Niemann played 38.Qxf8+! White gave up the queen for the rook. This idea is called removing the defender: when one piece guards the square you need, you take it away. After 38...Bxf8 39.Rxf8+, the white rook takes the bishop, with check. After 39...Kxf8 40.c8=Q+, the pawn becomes a queen, also with check.

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After 39.Rxf8+. Both defenders of c8 are gone, and the c-pawn will become a queen next move.

Analyze this position in the full game

Count the pieces after 40.c8=Q+. Each side has a queen, but White also has a bishop on h3. White is a whole piece up. The new queen then chased the black king with 40...Ke7 41.Qe6+ Kf8 42.Qf5+, and Mishra resigned.

Look closely at that last check. The queen on f5 gives check and also attacks Black's queen on g5. The bishop on h3 protects f5. If Black trades queens with 42...Qxf5, then 43.Bxf5 leaves White with a bishop against no pieces at all.

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The final position, after 42.Qf5+. The queen checks the king and attacks the black queen on g5, and the bishop on h3 guards f5. Black resigned.

Analyze this position in the full game

What about the other moves?

After 38.Qxf8+, Black had only two legal moves: 38...Bxf8 or 38...Kh7, stepping aside. Kh7 fails too: 39.Bf5+ leads to a forced checkmate in six moves, as our engine confirms.

Why not promote straight away with 38.c8=Q? Because Black simply takes the new queen with 38...Rxc8. The rook on f8 is still guarding c8. That is exactly why it had to go first.

One honest footnote: our Stockfish run at depth 22 rates 38.Be6+ as slightly stronger than the queen sacrifice. Both moves win easily. The engine's move is colder. Niemann's is the one people will remember.

What you can steal from this game

First, passed pawns must be pushed. Niemann's win came from the c-pawn created on move 33 and pushed on move 37. A passed pawn that stays at home does not win anything.

Second, learn to remove the defender. When one piece stops your plan, ask what happens if that piece disappears. 38.Qxf8+ did not move the pawn. It removed the only piece guarding the pawn's path.

Third, check the replies. A sacrifice you have not calculated is a blunder with good intentions. Niemann's worked against both 38...Bxf8 and 38...Kh7. That is what makes it a combination and not a gamble.

The rest of Round 4

Jeffery Xiong beat Awonder Liang in 68 moves, Liang's first loss of the event. Liang had won the first two rounds and drawn the third, and stays on 2.5 points. Xiong climbs to 2.

Grigoriy Oparin won with the black pieces against Sam Sevian, also in 68 moves. Oparin reaches 2 points and Sevian stays on 0.5.

Fabiano Caruana beat Ray Robson in 77 moves and joins So on 3 points.

Wesley So drew Levon Aronian, and Sam Shankland drew Andy Woodward.

Standings after Round 4

So 3, Caruana 3, Liang 2.5, Woodward 2.5, Aronian 2, Shankland 2, Xiong 2, Niemann 2, Oparin 2, Mishra 1.5, Robson 1, Sevian 0.5.

Tuesday is a rest day. Round 5 is on Wednesday, 14 October.