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Select a node in the repertoire move tree.
Load a PGN file to begin.
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Stockfish 18
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Game Data
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Expected Moves
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Opening Lab helps you build, store, analyze, and train chess opening repertoires. It combines PGN repertoires, move-tree browsing, explorer data, reports, and spaced training in one workflow.
An opening repertoire is your prepared set of lines for the openings you choose to play. It defines which positions you aim for, which opponent replies you are ready to meet, and where your middlegame plans begin. Ambitious players need one because it makes opening study concrete: you can avoid random memorization, repeat important positions, identify gaps, and build confidence in the structures you actually play.
Use Load Repertoire to upload opening files/PGNs you may already have created or acquired or to simply load one or more of the free Opening Lab repertoires that provide repertoires for White and Black for different levels/depths. Alternatively, use Create Repertoire to build a new repertoire or new lines for an existing repertoire, including suggestion-assisted creation when available.
Your repertoires are listed under Repertoire Analysis on the main page. From there you can open the move tree for each repertoire, review included lines, export PGN/PDF, rename or delete repertoires, and access analysis or critical-position reports.
Edit and tagging functions can be accessed through training or the move tree and let you add or remove moves, tag lines, annotate positions, and mark critical positions.
Start with Create Repertoire, choose the side you want to prepare, and enter the opening moves on the board. You can add lines manually, use suggestions where available, and later refine the move tree with edits, tags, annotations, and critical-position markers.
Repertoire views can show move-tree structure, included Daily status, explorer popularity by source and filters, critical-position reports, and analysis findings for weak or risky repertoire spots.
Open Repertoire Analysis from the main page, find the repertoire in the library, and use the PDF export button. The export gives you a printable repertoire tree.
Daily Training creates a plan to learn all repertoires marked as Daily in Repertoire Analysis. It supports efficient learning by using spaced repetition. The number of daily moves to be trained is defined so it allows steady progress in learning the relevant repertoires.
When enabled, the app can show an arrow for a move the first time it appears as a new prompt. That guided prompt introduces the move; later attempts count as normal training.
Use the ? button in the training modal to reveal the expected move. After revealing, play through the move and continue; the position remains useful for review instead of becoming a guessing exercise.
If training is still in the same line, use Open Analysis before continuing to review the position, options, evaluations, and to navigate back and forth in the line. You can also use Show Top Moves or look at Master Games from that position. In any event, the position where you made the wrong move will be shown again at the end of training and repeated until you get it right, giving you another opportunity to review it with the same tools.
Choose a repertoire, side to train, and training mode. Random Lines, Random Positions, Specific Line, and Critical Positions provide different ways to focus the session.
Training Entry Mode controls where Daily or Individual Training starts within a line. Due Moves Only prompts only the selected Daily target moves and autoplays access moves. First New Move starts from the first unresolved move needed for the selected line. Always Start At Move 1 starts from the beginning of the line and asks the relevant own-side access moves before the target.
Training Entry Mode controls where a line starts, After Line Completion controls manual or automatic advance, First-Time Guidance can show a first-time arrow, and Auto-Play Speed controls movement to the next prompt.
The training modal shows the board, current prompt, move history, expected moves when relevant, feedback, and explorer or engine context depending on the position and mode.
Either select Next Daily upon completion of Daily Training or use Individual Training after Daily Training. Pick the repertoire and mode you want, or use Random Lines/Random Positions/Critical Positions to continue practising beyond the daily queue.
Go to Individual Training, select a repertoire that contains the relevant opening and then select Specific Line to browse the exact opening or opening line you want to practise.
In Individual Training, change Side To Be Trained from Own Moves to Opponent Moves. The app will prompt you for the opponent-side moves from the selected repertoire.
It checks repertoire positions against explorer data and reports practical risks, missing replies, and positions where opponents score or choose important alternatives.
Green moves are already covered by your repertoire from the current position. Warning-coloured moves are popular or high-scoring opponent options in the selected game data and may deserve repertoire coverage or review.
Open Main Settings and adjust the explorer source, time controls, and rating buckets so the game data matches the pool you care about. For reports, use Report Breadth & Depth: lower settings are faster and stricter; higher settings inspect more positions.
It controls how broadly and deeply analysis searches. Low is faster and narrower; higher settings inspect more positions and require more time.
Game Reviews compare played games with your repertoires so you can see where your games followed, missed, or left prepared lines.
Use Game Reviews to compare your online games against your repertoires. When the report finds deviations, use Train Errors to practise the relevant repertoire positions.
Repertoires and training state are stored in the browser and, when signed in, synced through your Opening Lab account. PGN/PDF exports are available from the repertoire library.
Choose how to load a repertoire.
Manage your imported repertoires here.
Create a name tag for this critical position.
Save line tags and position annotations independently.
Review the line, navigate through it, and edit the ending safely.
Game Data
Loading position data...
| Move | Eval ~ | Share | White | Draw | Black |
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Edit Notes
Draft moves can only be added at the end of the line. Use Next ▶ to reach the line end, or move to an earlier move and delete it ⌫ (and the following moves) to add a new move. Saving requires the line to end with 'your' move. Selecting new opponent moves will be treated as an additional line. Note that if you delete one of 'your' moves, it may delete that same move (as well as all following moves) in various other lines that feature the same position!
Analysis Observations
Edit your notes for findings tied to this line and save with ✓.
Choose side and repertoire mode first.
Repertoire Side
Creation Mode
Coverage Scope (New Repertoire)
Add moves at the line end by click or drag-and-drop.
Game Data
Loading position data...
| Move | Eval ~ | Share | White | Draw | Black |
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Explanatory Notes
Add lines to the repertoire by moving the pieces on the board. To ease the building process you can also ask for suggestions 💡 on what to cover next by using the suggestion button. Save ✓ stores the line; if the draft currently ends with an unanswered opponent move, that final move is omitted automatically.
Connect your accounts and run the report to list deviations from your repertoire.
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Generate a report of your marked critical positions.
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Run the analysis to generate findings for the active repertoire.
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Selected repertoire: -
Please note that more breadth and depth will create more report findings. So specifically for smaller repertoires, it may make sense to start with low breadth & depth to catch the most important issues before diving deeper.
Load a position and click Master Games.
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