Modern Defense: the most common mistakes at each level
Which moves do club players really get wrong in the Modern Defense? We counted every move in up to 1,000,000 rated Lichess games per rating band (May 2024) and let Stockfish judge the frequent ones.
The most common Modern Defense mistakes, by level
Sorted by how many games they happened in. Click a card, then play the punishment on the board yourself.
1200–1400: the most common mistake is 3.Bxf7+? in the Modern Defense, played in 3% of the 1,465 games that reached the position.
1500–1700: the most common mistake is 4...Bg4? in the Modern Defense, played in 13% of the 252 games that reached the position.
How these numbers are made
We took rated Lichess games from May 2024 with a time control of at least three minutes, in which both players were rated inside the same band (1200–1400, 1500–1700 or 1900–2100) and no more than 200 points apart. For every position in the first ten moves we counted which moves were played. Stockfish then checked every move that at least a few percent of the players chose, and a move appears here when it costs at least one and a half pawns and leaves the player clearly worse. The percentages are for that exact move order.
Now train the patterns
The puzzles are the same kind of moment: a real mistake from a rated game, and you find the punishment.
3.Bxf7+? in the Modern Defense
3% of the 1,465 players rated 1200–1400 who reached this position played it. Stockfish: +0.5 before, -4.7 after (plus is good for White).