Chessational helps you memorize chess opening lines using spaced repetition. Import your Lichess studies, and the app will quiz you on lines—prioritizing the ones you struggle with or haven't seen in a while.

You can also import your Chess.com games to see where your actual play differs from your prepared repertoire.

Go to the Studies tab and paste a Lichess study URL or ID. The study must be public. All chapters will be downloaded and stored locally in your browser.

• Add: Paste the URL and click Add Study
• Refresh: Re-download a study after making edits on Lichess
• Delete: Remove a study from your browser (doesn't affect Lichess)

A line is a sequence of moves from the starting position to a leaf node in your study. You have one move per position; your opponent may have multiple responses, creating branches.

The system handles transpositions intelligently: if a line reaches a position that exists elsewhere in your study (even in another chapter), it follows those continuations automatically. This means maximum practice coverage without duplicating content.

In the Practice tab, select your studies and chapters, then click New Line. The board shows a position—make your move. Correct moves advance the line; incorrect moves are flagged.

• New Line: Get a fresh line to practice
• Restart Line: Try the current line again from the beginning
• Show Solution: Reveal the correct move with an arrow

Lines aren't random. The algorithm prioritizes based on:

1. Never-practiced lines — new lines you haven't seen yet
2. Weak lines — lines where you've made recent mistakes
3. Stale lines — lines you haven't reviewed in a while

Success rates use time-weighted probability—recent attempts count more than old ones, modeling how memory actually works. Check the Stats sub-tab to see your performance per line.

The Tree sub-tab in Studies shows your repertoire as an interactive diagram. Click nodes to explore positions. White and Black repertoires are shown in separate tabs.

The Games tab lets you import games from Chess.com. Enter your username and a date range, and the app downloads your games and builds a move tree.

Click Compare to Repertoire to see:

• Deviations: Where you played differently than your prep
• Gaps: Opponent moves that aren't covered in your repertoire

Use this to identify weak spots in your knowledge and find lines to add to your Lichess study.