Build an opening repertoire

A repertoire here is built on the board, one move at a time. A move you did not enter yourself — filled in for you by the app or by the opening book — is a move you never went through, thought about or made your own. So every move in your repertoire is one you played; the opening book stands beside the board as a reference, never as the author.

Start one

Practise tab → Opening repertoire → Open repertoire. New repertoire begins one: you say which side you are preparing, White or Black, and which opening — Choose opening, or Paste position (FEN) to start from a particular position rather than from move one.

Play the moves

In Build, play the move you would play. It is in your repertoire the moment you play it — there is nothing to accept.

• Your move. When you play it for the first time, the most played reply from master games is added with it, and the board moves on past that reply. That one move is the only one the app ever adds: it keeps you from preparing a careful answer to a sideline while the main continuation is missing.
• The opponent's moves. To prepare another reply, go back to your move — tap it in the tree, or step back with the arrows under the board — and play the opponent's move you want on the board. Any legal move works, including one the book has never seen.

A good habit: for your side, one move per position; for the opponent, one or more.

What helps you choose

• The book. Beside the board, with the engine's lines (under it on a phone), the moves played from this position in master games, each with how often it is played and in how many games. Tap one to play it. ★ marks your main move, ✓ a move already in your repertoire.
• Ask engine — what Stockfish thinks of the position on the board, whichever side is to move. It is worth asking when the book has run out and there is nothing else to go on.
• Ask AI about position — what stands on the board and what is threatened, in words. The engine analyses the position first and the sentence is checked against that analysis before you see it. It is written in the language chosen under Comments in in Analysis's Study this position.
• Comment on position — your own note, which is what you will read when you meet the position again; Add to my comment keeps what was suggested.

Find your way around

The tree beside the board is your repertoire. A number beside the opponent's move says how often it is played; ? marks a position where you have not chosen a move yet. Next position takes you to the next one. Show entire repertoire and Show only from this position choose how much of the tree to look at.

Rehearse it

Drill plays the opponent's side — the moves you prepared — and asks you for yours. Drill branch and Drill this branch narrow it to the part you are working on, Skip rehearsal passes a position you know, and Next position moves on.

Positions you have drilled come back on their own, spaced out over time, the next time you drill the repertoire.

Tidying up

• Long press a move in the tree (or right click it) to delete it — yours or the opponent's. If moves of yours come after it and nothing else leads to them, you are asked first.
• Extract into new opening — split a branch off as a repertoire of its own.
• Delete moves from database — empty everything saved for White or for Black, with the question asked first.

Taking it out of the app

Export as PGN, on a repertoire's own menu in the list, writes the whole tree as a PGN file: your main move is the main line, the other moves you kept are its variations, and the notes you wrote travel with them. Save as .pgn puts it where you choose, and the text is on the clipboard as soon as the window opens.