Two Pieces Attacked at Once: Wesley So Beats Caruana in the Playoff and Wins His Fourth U.S. Title

Photo: Frans Peeters Photography / Wikimedia Commons (CC BY-SA 2.0)

Wesley So is the U.S. Champion again. On Thursday in Saint Louis, he beat Fabiano Caruana in a playoff, 1.5 to 0.5. It is his fourth U.S. title, after 2017, 2020 and 2021.

The two of them had finished the 11 rounds tied on 7 points. So had needed only a draw in the last round, but Samuel Sevian beat him in a rook ending. That sent the title to a playoff.

The playoff was rapid chess: each player had 15 minutes for the whole game, plus 10 seconds for every move. Two games. The first was a draw. So won the second with the white pieces in 33 moves.

The second game turned on one moment. Try it yourself first.

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Black to move. Two black pieces are under attack. Can you find the one move that keeps them both? The answer is further down.

Analyze this position in the full game

Here is a hint. Look at the white queen on c3. Which black pieces can it reach? Now look at the white pawn on f4.

Game 1: So misses his chance

Caruana had the white pieces in the first game. It began 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2, the Nimzo-Indian Defense, the same opening Sevian and So played the day before.

For 20 moves the game was calm. Then So got on top. After 25.Qb6 Bxe5 26.fxe5 Qc3 27.Rc1 Qxe5, his queen had taken a pawn. So was a pawn up, and he had a pawn in the center on d5.

That pawn ran. After 28.e4 d4, it moved forward, and a few moves later it stood on d3. Caruana pushed a pawn of his own. By move 36 our engine rated So more than two pawns better.

Both players were very short of time. Caruana had 24 seconds left after his 33rd move. So had 46 seconds after his 36th. Then So played 36...Rd8, and the game turned. Our engine wanted 36...Ba4, which kept Black well on top. After 36...Rd8, Black was only a little better.

37.Qb7 d2 38.c7 came next.

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After 38.c7. Look at the two pawns. The white pawn on c7 and the black pawn on d2 are each one step from becoming a queen. Black to move.

Analyze this positionReview the full game

This is a pawn race. Each side has a pawn one step from the last row, where it can become a new queen.

Neither pawn became a queen right away. Many moves later, Caruana's king took the pawn on d2 with 53.Kxd2, but his own pawn on c7 was still alive. Later, he gave up his queen for So's rook with 63.Qxf8+ Kxf8, and after 64.Rd8+ Ke7 65.c8=Q, the c-pawn became a new queen.

But So still had his queen, and he started to check the white king: 65...Qf1+ 66.Kh2 Qf4+ 67.Kg1 Qe3+ 68.Kf1. He kept checking until the same position had come up three times. When that happens, the game is a draw. This is called a draw by repetition.

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The final position of Game 1. White has a queen and a rook. Black has only a queen, but its checks brought the same position three times. Draw.

Analyze this positionReview the full game

The Game: So v Caruana

In Game 2, So had the white pieces. A win would make him champion. The game began 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.d4 Bb4, a line of the Four Knights Game.

So took a pawn with 5.Nxe5. Caruana castled with 5...O-O and won the pawn back a few moves later: 6.Qd3 Re8 7.Bd2 Nxe5 8.dxe5 Rxe5.

Then So made the choice that shaped the whole game. He played 9.O-O-O, castling on the queenside.

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After 9.O-O-O. The white king is on c1, on the queenside. The black king is on g8, on the kingside. Black to move.

Analyze this position in the full game

When the two kings castle on different sides of the board, it is called opposite-side castling. It usually means a race. Each player pushes the pawns in front of the other king, to break open his shelter. A file is a column of squares, like the g-file or the h-file. Here, White's pawns on the g-file and h-file face the black king. Black's pawns on the a-file and b-file face the white king.

The pawn race

So went first. After 9...d6 10.f3 Bd7 11.g4 Bc6 12.g5 Nd7 13.h4, his pawns were moving toward the black king. Caruana raced back with 13...b5 14.Kb1 a5 15.h5 Nc5 16.Qe3 Rb8 17.Ka1 a4 18.Bh3 a3.

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After 18...a3. Both sides have pawns near the enemy king. The black pawn on a3 attacks b2, close to the white king on a1. White to move.

Analyze this position in the full game

Look at both sides of the board. White's pawns stand on g5 and h5. Black's pawn stands on a3, next to the white king. So answered with 19.b3. Now the black pawn on a3 had nothing to take, and the files next to the white king stayed closed. The clock was a problem now too. After 18...a3, Caruana had under two minutes left.

Two pieces attacked at once

Caruana played 19...Ne6. So answered with 20.f4.

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After 20.f4. The white pawn on f4 attacks the black rook on e5. Black to move.

Analyze this position in the full game

The pawn on f4 attacked the rook on e5. Caruana answered with a check, 20...Bxc3+, and So took back with his queen, 21.Qxc3.

That brings us to the puzzle position from the top of this article. Look at what the white queen on c3 does now.

• It looks straight up the c-file at the black bishop on c6. Nothing guards that bishop.
• It looks along the long diagonal at the black rook on e5. The pawn on f4 attacks that rook too.

When one move attacks two pieces at the same time, it is called a double attack. Here the queen hit two black pieces, and Black could only move once.

Here is the answer to the puzzle: 21...Rc5. The rook steps away from e5, and on c5 it stands between the white queen and the bishop on c6. One move saves both pieces. Black had 35 legal moves in that position. Our engine checked every one of them, and 21...Rc5 was the only one that did not leave White about a piece ahead.

Caruana played 21...b4. The pawn attacked the white queen. But the queen did not need to run away. It took the bishop instead: 22.Qxc6.

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After 22.Qxc6. The white queen has escaped the pawn on b4 by taking the bishop. White is a whole bishop ahead. Black to move.

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The finish

Now So was a bishop ahead, and Caruana was almost out of time. After 22...Rc5 23.Qa6 Rcb5 24.Bf1 Nc5 25.Qc6 Ra5, Caruana had 15 seconds left on his clock.

So kept his extra piece. 26.Qd5 Qe7 27.Bg2 Rab5 28.Kb1 Ne6 29.Qd3 h6 30.gxh6 Qf6 31.Bc1 Nxf4 32.Qf3 g5.

Caruana's last move pushed the g-pawn two squares, from g7 to g5. It landed right beside the white pawn on h5. That is when a special rule can be used: en passant, which is French for "in passing". A pawn that moves two squares and lands right beside an enemy pawn can be captured as if it had moved only one square. So did just that: 33.hxg6.

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The final position, after 33.hxg6 en passant. White is a piece ahead, and two white pawns stand on g6 and h6, right in front of the black king. Black resigned.

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Caruana resigned, which means he stopped the game and accepted the loss. So finished with 2 minutes and 17 seconds on his clock.

Two old rivals

Caruana has won the U.S. Championship five times, in 2016 and in every year from 2022 to 2025. This year he finished second.

So and Caruana had already met in Round 9 of this event, and that game was a draw. This is not the first time So has beaten Caruana in a playoff, either. In March, at the American Cup in Saint Louis, he beat him in a blitz playoff. And his 2021 U.S. title also came in a playoff, against Caruana and Sevian.

What to Learn

• When the kings castle on opposite sides, attack with your pawns. So pushed his g-pawn and h-pawn toward the black king. Caruana pushed his a-pawn and b-pawn toward the white king. In races like this, speed matters.
• Look for double attacks. One white queen move hit the bishop on c6 and the rook on e5 at the same time.
• Before you attack, check what is already attacked. 21...b4 hit the white queen, but the queen could escape by taking the bishop. 21...Rc5 saved both black pieces in one move.
• Know the en passant rule. A pawn that jumps two squares past an enemy pawn can still be taken, as if it had moved one square.
• Count the checks. In Game 1, So could not win, but his queen checked the white king until the same position came up three times. Repetition saved a draw.

We checked these games with Stockfish 17.1 at depth 20. The key positions were checked deeper, at depth 24, and on move 21 of Game 2 we checked every legal move one by one.

Update: Caruana is back at the board in Saint Louis this week. Here is what Clutch Chess asks of him.