Risky pre-moves in online chess
Are the top players disciplined, or could a daring opponent predict and exploit their pre-moves?
In online chess, especially in blitz and bullet time controls, players save time by "pre-moving," selecting a move to be executed automatically as soon as their opponent moves.
While pre-moving is a key part of the game, it's not without risks. A pre-move operates under the assumption that the opponent will play a particular move. If the opponent deviates from what's expected, the pre-move could lead to suboptimal or even disastrous positions.
The PGN for an online game often includes timestamps for all the moves, so we can pretty-well guess which moves were pre-moves. On chess.com, for example, a time delta of 0.1 second indicates a pre-move. This tool analyzes each detected pre-move to check if the opponent could have played something unexpected to improve their position.
Play with the tool below to find out by pasting PGN into the box. You can also load a random game from chess.com using this form:
You can also visit the gallery of recent examples.
Pre-move vulnerability analysis tool
The tool runs stockfish 10 in the browser using wasm and stockfish.js. PGNs are processed using chess.js and displayed using PgnViewerJS. I also learned from nice examples at stockfish-chess-web-gui, so thank you to LabinatorSolutions for making them available.