AI chess opponent preparation

My Second is the opponent-preparation module of ChessMoves AI. Give it an opponent and it studies their games the way a professional second would: what they play, how they answer your repertoire, where they score badly and where they go wrong. Then it lets you rehearse the game against a simulation of them.

The workflow

Identify the opponent. Look them up on Lichess, Chess.com or FIDE, upload a PGN of their games, or pick them from a tournament broadcast you are playing in.
Analyse their historical games. Their games are downloaded and checked with Stockfish, so their mistakes are found by an engine, not guessed.
Analyse their opening repertoire. Opening trees for their games as White and as Black, with how often they play each line and how they score in it.
Identify their recurring variations. The lines they return to, and where they leave them.
Identify their playing tendencies. The moves where most of their mistakes happen, the phase they struggle in, their time management, and the tactical themes they miss.
Identify the important positions. The game plan names the critical positions: where your preparation meets theirs, the branch they handle worst, and one of their typical errors.
Prepare recommended lines. Their most likely reply to your saved repertoire, their weakest branch to aim for, and a strategy drawn from those numbers.
Train against the opponent. Play a whole game against a simulation of them, then drill the positions it shows you were not ready for.

The game plan

For the colour you will have, the game plan states, each with the number of games behind it: their likely opening, their reply to your repertoire, their weakest branch, the move numbers where their biggest errors cluster, a strategy, and three critical positions. Nothing is claimed from fewer than three games.

Opponent Simulation

A whole game against a model of your opponent, with a clock at their usual time control. While the game follows their games, it plays their own moves, as often as they chose each. After that it plays the move a human of their rating makes in that time control (Maia-2). In the stretch of moves where they make most of their mistakes it plays the full human spread; elsewhere it leans towards the likeliest move, so its errors come where theirs do. It also leans towards the pawn structure they reach most often, and every move says where it came from.

After the game you get an opponent-prep score (half how far your preparation held, half your accuracy), what you anticipated and what you missed, and three positions that go straight into training. It is not a network trained on one player, and it does not model their endgames.

Briefs, questions and tournaments

Each opponent gets a written scouting brief grounded in their own games, and you can ask questions about them in a chat that answers from those games. For a tournament, prepare the whole field in one go, or follow a live broadcast and prepare the next pairing as it is published.

Who can use it

My Second is part of the paid plans; a free account can scout one opponent a month. The subscription terms list the plans and their prices.