Grandmaster Blunders You Can Solve: World Championship, Candidates and the Majors

Short answer: Pro Blunders is 731 puzzles built from the moments the world's best went wrong, in World Championship matches, the Candidates and the majors. You find the move a grandmaster missed, or punish the one they played, and Stockfish checked every answer. It's free with a KingChess account, and a new Blunder of the Day arrives each morning from the top fifty blitz players on Chess.com.

Every chess player has watched a grandmaster drop a piece on a live broadcast and thought: I would have seen that. Now you can check. Below are four positions from the sets, with the answers folded away. Set the board up in your head or on a real one, decide, then open the answer.

Where the positions come from

Lichess relays the big events move by move, and its engine marks each mistake as it happens. Pro Blunders takes every move marked a mistake or a blunder in an event and asks Stockfish a harder question at depth 22: is there one clear answer here?

A mistake becomes a puzzle in one of two shapes. When the move the player should have found is the only move that holds or wins, you play their side and find it. When several moves would still have held, the puzzle flips: you play the other side and punish the move they made. Only about one marked mistake in four passes. The rest are thrown out, because a puzzle with two right answers teaches you nothing.

Twenty events are in so far, from the 2022 Candidates to the 2026 Sinquefield Cup. The 2025 Grand Swiss alone gave 310 puzzles from 638 games. Each set keeps your solved count, and every puzzle links to the game on Lichess.

Four to try

The move that lost a World Championship

Game 14, the last classical game of the 2024 match, with the score level. The rook endgame with a bishop each had been a draw for a long time. Then Ding put his rook on f2. Punish it.

Show the move

55...Rxf2. After 56.Kxf2 Bd5 the bishops come off too, and the pawn ending is lost for White. Ding resigned three moves later, and Gukesh became World Champion. The game on Lichess.

The win Caruana walked past

The last round in Toronto. Caruana needed a win to catch Gukesh at the top. He has a queen and a rook against a queen and a knight, a pawn on f7 one step from queening, and the move. Find it.

Show the move

66.Qe8+ wins. Caruana played 66.Qc6+ instead, the game was drawn, and Gukesh went to the World Championship match. The game on Lichess.

Ding, mated in three

Ding's rook has just landed on b2, hitting the bishop and eyeing the back rank. It looks active. It loses by force. Punish it.

Show the move

30.Qxh7+ Kxh7 31.Rh4#. The queen sacrifice clears h7, and the rook lift along the fourth rank is mate. Carlsen played it. The game on Lichess.

Round one of Candidates 2026

Queen and bishop each, and a long grind. Caruana is better, and there is one move that ends the discussion. Find it.

Show the move

67.Qe6+ wins at once. Caruana played 67.f4, which let Black back into the game, and still went on to win. The puzzle counts the quicker win. The game on Lichess.

Blunder of the Day

The sets are history. Blunder of the Day is yesterday. Every morning the engine reads the previous day's blitz games of the top fifty players on the Chess.com blitz leaderboard, a couple of games each down the ranking. It evaluates every position in them and keeps the moves that threw away two pawns or more from a calm position. Then it takes the highest-rated player's worst moment first and puts it through the same check as the sets. The first one that passes is the day's puzzle.

It is a different kind of mistake from the ones above. These are three-minute games, the players are rated 3200 and up, and the blunders look like yours: a piece left hanging, a tactic missed with two minutes on the clock. Here is the first one the system built, from the games of October 26.

Show the move

17.Bxf6. The bishops take turns: 17...Bxd1 18.Bxd8 Bxc2 19.Bxa5, and White comes out a piece up. The engine's read went from level to three pawns better for White in one move. Paravyan won. The game on Chess.com.

On the morning of October 28, members got Ediz Gürel against Dmitry Andreikin. Tomorrow it will be someone else. The last two weeks stay open, so a missed day is not gone.

Why solve grandmaster blunders?

Because the shapes are the same as yours. A rook that strays from the back rank, a queen that wanders off the defence, a check that was there and was not seen. The difference between a 3300 and a 1300 is not that one of them never does this. It is how rarely, and how fast they notice.

There is a second reason, and it matters more. The puzzles that teach you the most are still the ones from your own games, because those are the shapes you personally keep missing. Pro Blunders is the fun room. Your own blunders are the gym. KingChess reads your Chess.com or Lichess games, finds the mistakes that keep costing you, and turns those into puzzles too.

Pro Blunders and Blunder of the Day are made by KingChess. They read public broadcast games from Lichess and public game archives from Chess.com, and are not affiliated with either site.