How to prepare for a chess opponent

ChessMoves AI · 7 October 2026

Preparing for a named opponent turns hours of general opening theory into the few lines that will actually come up, and tells you what kind of game to aim for. Here is a method you can follow, by hand or with software.

1. Collect enough of their games

You need their games at a time control close to the one you will play, and enough of them to see patterns: twenty is a start, fifty is better. Online accounts (Lichess, Chess.com), FIDE-rated games from databases and tournament broadcasts are the usual sources. Recent games matter more than old ones: repertoires change.

2. Read their repertoire with your colour in mind

If you will have White, only their games as Black matter, and only those that began with your first move. Build an opening tree: at each move, what they chose and how often, and how they scored. Look for the line they play most and the point where your own preparation meets it.

3. Find where they score badly, and where they go wrong

Two different things. A weak branch is a line after which their results drop: three losses in four games after one particular move of yours is worth knowing. A recurring error is a phase or a kind of position where their mistakes cluster: some players collapse around move 20, some in endgames, some when short of time. An engine check of their games shows where, rather than guessing from results.

4. Choose your lines, and check them against theirs

Pick lines that steer towards their weak branches and away from where they are comfortable. Then walk your prepared line through their games: where do they leave it, and what do they play instead? That move is the one to prepare for. Do not prepare twenty moves deep against a player who leaves theory at move eight.

5. Rehearse

Play the critical positions out, from both sides, until the plans are familiar. If you can, play a whole training game in which your opponent plays the way they actually play, then review where your preparation held and where it did not.

Doing it with ChessMoves AI

AI chess opponent preparation in ChessMoves AI does each step: it downloads and engine-checks their games, builds their opening trees, walks your repertoire through them, names their weakest branch and their error window, and lets you play a game against a simulation of them, then drill the positions you were not ready for.