iImport details of opponents from Lichess, Chess.com or PGN. Analyse their games and opening repertoire, looking for weaknesses in their games. Save and organise their details ready for future games. Add your own details to evaluate your own games and repertoire too.
♞
Your Profile
Saved Players
No saved players yet.
♞
Player Name
Fetching games...
Manual online chess lookup
Find Player through online team / club
Import PGN
Paste one or more games in PGN format to create an opponent profile. You can export PGN from ChessTempo, 365chess, or any chess database.
Searching...
Search Results▼
Chess.com Results▼
Lichess Results▼
Opening Repertoire
Inactive account
Filter:
Note: Lichess only shares the most recent 200 games.
As White
As Black
(Please check all highlighted weaknesses carefully. Identification errors can occur)
Opening Weaknesses
Games —
Repertoire Summary
iBrowse, organise, and review your saved games or interesting positions. Use folders and tags to keep everything organised, and search, sort and filter to find the exact game or position you want to analyse.
Saved Games, Analysis and Positions
Saved Games, Analysis and Positions
Manage Tags
iUpload PDFs of chess books or magazines and study them in a full-screen reader. Play along with the games or set up book puzzle positions using a digital board.
Chess Books
Chapters
Bookmarks
Fit
Play Along
Setup Position
✖
Keyboard Shortcuts
← / → Prev/Next page ↑ / ↓ Prev/Next move Home / End First/Last page F Flip board R Reading mode Space+drag Pan PDF Space+wheel Zoom PDF
Touch Gestures
Swipe ◀▶ on board — Prev/Next move Swipe ◀▶ on page — Prev/Next page Tap piece then square — Move piece Pinch on page — Zoom in/out
iBookmark, tag, and watch your favourite YouTube chess videos. Track your watching progress with Keep Watching.
iCreate structured training sessions combining puzzles, books, bot matches, and more. Launch your training session and keep track of its progress. Subscribe to your training calendar in your favourite calendar app.
Training Sessions
New Training Session
Training Calendar
Today's Training
Recent Activity
00:00
Live Broadcasts
Loading broadcasts...
Commentary
iPlay against a chess bot at any strength, or challenge a bot playing a saved player's opening repertoire, or even your own!
Play vs Bot
Playing from custom position
Your colour
Bot type
Approximate rating (OTB / FIDE)
1500
Intermediate
Time control
Countdown timer (optional)
Your time to win the position. Bot has no time limit.
The bot will share its thoughts during the game
Bot--:--
You--:--
Your turn
#
White
Black
iLook up any UK chess player by name to see their ECF and FIDE ratings and recent game results. Save and group players for future reference. Add information about the teams you represent and link to online league information to stay up to date.
Captain Tools
Search ECF Players
Tip: search by club alone (with no player name) to see all players affiliated with a club.
My Info
Search for yourself below and click “This is me” to set up your profile card.
Saved Players
Teams
Add a Team
My Fixtures
♟
Searching...
iCustomise your experience — board style, puzzle filters, and account settings.
Account
Logged in as
Display Name
Shown in bot matches and game scoresheets.
Profile Avatar
Displayed in the header and on the Players tab.
♞
Board Appearance
Customise board colours and piece style across all boards.
Limits how deep the local (browser) engine searches. Does not affect cloud engine. Lower depths use less CPU and battery. Eval graph always uses depth 18.
Online Accounts
Your Lichess and Chess.com handles. These are used to identify your games when importing from those platforms and to highlight your games in Player Research. The same handles appear in Player Research → Your Profile.
Export your games, players, folders, and settings to a JSON file for safekeeping. Import a previously exported file to restore data.
Your backup data is ready. Use the download button to save.
What Gets Exported
Puzzle Stats
Analysis
The Analysis board is the heart of Icarus Chess. Load or play through games, run engine analysis, annotate with comments and variations, and share positions or animated GIFs.
Main analysis view with board, move list, engine lines, and toolbar
The Board
The interactive board displays the current position. Drag pieces to make moves, or click a piece then click its destination square. Right-click (or long-press on mobile) for display options including toggling last-move highlights and engine arrows.
Toolbar
Analysis toolbar
The toolbar below the board provides quick access to key features:
▶ Play
Full-screen play-through of the game with auto-advance. Also exports animated GIFs.
Game Info
View and edit game metadata: players, date, result, event, opening.
Setup
Set up a custom position manually, from a FEN string, or by uploading/pasting an image of a board.
Load / Save
Load a previously saved game, or save the current game to your Games folder.
PGN↓
Import a game from PGN notation.
Share
Share a board position image, FEN, game link, PGN, or animated GIF.
↑Bot
Play the current position against a chess engine (Stockfish or Maia).
Live Games
Browse and follow live chess broadcasts from Lichess. Watch games in real time with clocks and optional YouTube commentary.
Engine Analysis
Engine analysis panel
Press E or click the engine button to start Stockfish analysis. The engine displays its top candidate moves as arrows on the board, along with evaluation scores and principal variations. An evaluation bar shows the balance of the position visually.
Cloud vs Local Engine
When Lichess has a pre-computed evaluation for the current position, Icarus uses that cloud eval instead of running the local Stockfish engine — it’s typically deeper and arrives instantly. If you’d rather watch the local engine work move by move, click Use local engine in the engine panel. The cloud database covers most positions in well-known openings and master games; for novel positions Icarus falls back to the local engine automatically.
Evaluation Graph
Click the graph icon on the analysis toolbar to evaluate every position in the game and produce a visual graph of how the advantage shifted throughout. Click on any point to jump to that position. Blunders and mistakes are highlighted in red, making it easy to spot critical moments where the game turned. Significant evaluation drops are automatically flagged with NAG annotations (?, ??) on the relevant moves in the move list.
Evaluation graph with blunder highlights
Deep Analysis
Deep Analysis runs a thorough server-side analysis of your game using Stockfish at high depth, Maia neural network for human-difficulty assessment, and AI-powered natural language annotations. Click the Deep Analysis button in the eval panel or use the re-evaluate button on the graph.
The pipeline runs five passes:
Quick scan — evaluates every position at depth 22 with 3 candidate moves
Maia scan — assesses how difficult each move was for a human to find
Deep scan — re-analyses critical positions (mistakes, blunders) at depth 26
Highlight detection — identifies great (!) and brilliant (!!) moves using chess.com-style criteria
AI annotation — generates natural language commentary explaining mistakes, good moves, sacrifices, and the game summary using Claude AI
What you get:
Move quality markers (!, !!, ?, ??, ?!) on every move
Engine alternative variations showing what should have been played
AI-written prose comments explaining why moves are good or bad in plain English
Opening identification with character description
A game summary with ACPL (Average Centipawn Loss) for both players
Periodic evaluation markers through the game
Engine-generated comments and variations appear in muted blue-grey, while your own annotations appear in gold. Use the toggle bar to show or hide engine comments and variations. Deep Analysis typically takes 3–5 minutes and you’ll receive a notification when it completes.
Variations & Annotations
Create variations by simply making alternative moves at any point. The move list displays the full variation tree. Right-click a variation move in the move list to promote a variation or delete it. Right-click also to annotate it with move markers (!, !!, ?, ??, etc.). Add text comments to any move for your own notes.
Opening Explorer and Master Games
When connected to Lichess via an API token, the opening explorer shows commonly played moves in the current position along with win/draw/loss statistics. Click any move in the list to play it on the board. Use the rating slider to see how opening choices differ across rating ranges. Browse master games that reached the position, filter them by year range, and import them as variations for study.
Sharing
The Share panel lets you share your games, analysis or position in multiple ways: copy a high-resolution board image to your clipboard, save it as a file, copy the FEN, export an animated GIF of the full game, create a shareable 'read only' viewer link, export PGN, or open the position on Lichess. Board images can optionally include the last move highlight, engine arrows, evaluation bar, and coordinates.
Share panelShared game viewer
Annotated PDF Export
From the Share panel, export the current game as a print-ready PDF. The document includes the full move list with your comments, variations, and NAG symbols, along with diagram images at key positions (openings, decisive moments, and any squares you have marked as key). Engine evaluations and an evaluation graph are included if the game has been analysed. The PDF is generated server-side and downloaded directly to your device.
Annotated PDF export — move list, diagrams at key positions, and evaluation graph
Live Broadcasts
Follow live chess events broadcast by Lichess. Click Live Games to browse current tournaments and rounds, or paste a Lichess broadcast URL directly. Select a game to load it onto the board with live-updating clocks and player ratings. Moves appear in real time with sound. If you make a move on the board to explore a variation, the broadcast pauses automatically — click Resume to return to the live game. You can also paste a YouTube link to open a commentary video alongside the board in a resizable, draggable panel.
Following a live broadcast with game list and YouTube commentary panel
Setup Position
Open the setup panel to create any position. Drag pieces onto the board, set the side to move and castling rights, or paste a FEN string. You can also upload a photo or screenshot of a board position — AI-powered image recognition (Claude Haiku) will detect the pieces and set up the position automatically. Paste an image with Ctrl+V / Cmd+V for even faster setup.
Setup position with piece palette and image recognition
Games
Your personal game library. Save games from analysis, organise them into folders, search and filter, and tag games for easy retrieval.
Organisation
Create folders to organise your games by opening, tournament, opponent, or any category you like. Move games between folders at any time. Browse by folder structure or switch to tag view to filter across all games by tag.
Browse by Folder view with game cards, folder breadcrumbs, search, and sort options
Search & Filter
Search games by title, player name, or content. Filter by result (White wins, Black wins, Draws, Decisive) and sort by date, player name, title, or type. Switch between large card, small card, and list views.
Browse by Tag view — filter across all games using tag chips
Tags
Tag games with categories like openings, themes, or custom labels. The tag view lets you browse all your games filtered by one or more tags, making it easy to find games across different folders. Use the Manage Tags button to create, rename, recategorise, or delete tags.
Manage Tags — create, rename, recategorise, and delete tags
Game Actions
Each saved game can be opened for analysis, edited, renamed, moved to a different folder, uploaded to Lichess, or deleted. Click any game card to load it into the Analysis board.
Play
Play against a chess engine from any position. Choose between human-like Maia bots or traditional Stockfish at adjustable strength levels, with optional time controls.
Play setup — choose colour, bot type, rating, and time control
Bot Types
Maia is a neural-network bot trained on human games. It plays human-like moves, including realistic mistakes at each rating level (1000–2200). Stockfish is a traditional engine with adjustable strength from beginner (400) to master (2800).
Play against a saved player’s repertoire — the bot mimics their opening choices
Game Options
Choose your colour (White, Black, or Random), set the bot’s approximate rating, and optionally add a time control (3+2, 5+3, 10+5, 15+10, or 30+0). A countdown timer option lets you set a time limit to win from a specific position. Enable or disable bot commentary for in-game chat.
Active game vs Maia (1400) with scoresheet and bot commentary
Play from Position
Use the ↑ Bot button on the Analysis toolbar to start a game from any position you’re analysing. The bot takes over from the current position. After the game, you can analyse the result or start a rematch.
Play from a custom position with optional countdown timerPlaying against a saved player’s repertoire bot
After the Game
When the game ends, you can analyse it in the Analysis board, save it to your Games library, start a rematch with the same settings, or begin a new game.
Training
Create structured training sessions with timed activities. Plan your study routine and track your progress with the training calendar.
Training sessions list with calendar view
Training Sessions
Create training sessions with multiple timed activities (e.g. 15 minutes of tactics, 20 minutes of openings, 10 minutes of endgames). Name your sessions and schedule them for specific days. Activities can link to specific sections of the app so you can jump straight to the relevant area.
Create a new session — choose from activity types like Puzzles, Book Study, Bot Match, and more
Timer
Start a training session to launch the timer overlay. It counts down through each activity, with pause, skip, and “go to” controls. The timer can be minimised or popped out while you work on the relevant area of the app. A progress bar shows how far through the current activity you are.
Training timer with activity list, pause, skip, and go-to controls
Calendar
The training calendar shows your scheduled sessions and completed activities. Navigate between months, jump to today, and click any day to see the detail. Subscribe to your training calendar in external calendar apps for reminders.
Today’s training — assigned session with activity breakdownSubscribe to your training calendar in Google Calendar, Apple Calendar, or Outlook
Videos
Build a personal library of chess instruction videos from YouTube. Organise, tag, and track your viewing progress.
Video library with tag filters, Keep Watching section, search, and channel filter
Adding Videos
Click “Add Video” to save a YouTube video by pasting its URL. The video’s title, thumbnail, and channel are fetched automatically. You can also install the browser bookmarklet to add videos with one click while browsing YouTube.
Add Video — paste a URL to fetch metadata and tag suggestions automatically
Watching & Tracking
Click a video card to open the embedded player. Videos you’ve started watching appear in the “Keep Watching” section at the top for easy resumption. Mark favourites with the star icon — favourited videos always appear first in the grid.
Video player with embedded YouTube, board position sync, and tags
Search & Filter
Search by title or keywords, filter by channel, sort by date added or published, and use tags to categorise your video collection.
Books
Upload chess books in PDF format and read them with an integrated play-along board. Recognise board positions directly from the PDF pages using AI image recognition.
Book library with folder organisation, covers, and book actions
Reading
Open a book to see the PDF reader alongside a play-along board. Navigate pages with arrow keys or swipe gestures, zoom in and out, and jump to chapters from the table of contents. Bookmark pages for quick reference. Toggle “Reading Mode” for a distraction-free view.
Book reader — PDF page with play-along board, navigation, and table of contentsReading Mode — text-focused view with clickable moves and board position
Annotation Tools
Click the pencil icon in the page toolbar to open the annotation toolbar and mark up any PDF page by hand. Annotations are saved per page and persist between sessions. The toolbar has two modes, picked explicitly to prevent accidental marks:
Move mode (four-headed arrow, default) — pan, zoom, and scroll the page without drawing.
Draw mode (pencil) — enables drawing. When selected, colour swatches (black, red, blue, green) and line thickness options appear on the toolbar.
Highlighter — a thick, semi-transparent yellow stroke. Multiple strokes over the same area darken naturally, but a single stroke stays uniform.
Eraser — tap to remove individual strokes.
Undo — removes your most recent stroke.
Add Note — creates a post-it note at the centre of the visible viewport. Drag notes to reposition, double-click to edit the text, or tap the × to remove.
Clear — removes every annotation on the current page (with confirmation).
On an iPad with Apple Pencil, the pencil draws while a finger pans. On touch-only devices (iPhone, non-pen Android), a finger draws in Draw mode and the Move mode button lets you pan instead.
Annotation tools — Move/Draw modes, colours, thickness, highlighter, eraser, undo, notes, position markers, and clear
Position Markers
In Annotation mode, click Position in the toolbar and paste a FEN to drop a small board-icon marker on the page. The icon sits over the diagram or paragraph it relates to and stores the position you typed. Tap or click the marker any time to load the FEN onto the play-along board — useful for jumping straight back to a critical position you’ve revisited several times. Drag a marker to move it; tap the × in edit mode to remove. Markers are saved per page alongside drawings and notes.
Favouriting Books
Each book card has a star button on the cover thumbnail — click it to mark a book as a favourite. Favourite books appear in their own “Favourite Books” section at the top of the Books page (above the regular folder/book list), so you can find the titles you return to most without drilling into folders. Click the star again to un-favourite.
Board Recognition from PDF
Open the setup position panel while reading a book. Click “Recognise PDF” to automatically detect the board diagram on the current page using AI vision. The recognised position is loaded onto the play-along board, where you can correct any errors and then play through the variations described in the book. For best results, zoom into the PDF so the board diagram fills most of the page.
Recognise PDF — AI detects the board diagram and loads the position for play-along
Send to Analysis
At any point while playing along, click “Send to Analysis” to load the current position into the main Analysis board for deeper study with the engine.
Player Research
Research opponents and study partners. Look up players on Lichess and Chess.com, fetch their games, analyse their opening repertoire, and even play against a bot that mimics their style.
Players panel — your profile, saved players in folders, manual lookup, team search, and PGN import
Your Profile
Connect your own Lichess and Chess.com accounts to import your games. Upload a profile avatar. Your profile data is used for personalised features across the app.
Looking Up Players
Search for any player by their Lichess or Chess.com username. You can also search by name within clubs and teams, filtering by country and rating range. Save players to your library for future reference, organised in folders. Each saved player can have personal notes — useful for recording observations, weaknesses you’ve spotted, or preparation for upcoming matches.
Game Fetching & Analysis
Fetch a player’s recent games automatically. Once fetched, the games are available for analysis. The system identifies the player’s opening repertoire — which openings they play most frequently as White and Black.
Opening repertoire — a player’s most-played openings as White and Black
Opening Weakness Analysis
Analyse a player’s opening weaknesses — moves they repeatedly play that give the opponent an advantage. The system evaluates the first 12 moves of every game with Stockfish and highlights recurring mistakes. Click any weakness to load the position in the Analysis board.
Opening weakness analysis — find patterns in a player’s bad moves with game examples
Play as Bot
Once a player’s games have been analysed, click “Play as Bot” to practice against their opening repertoire. The bot plays the openings this player is most likely to use, helping you prepare for an upcoming match.
OTB Player and Team Info (UK)
Look up any UK over-the-board chess player by name or ECF code. View their ECF and FIDE ratings, rating history, and recent game results. Save players for future reference, organised into groups. Add your own teams with links to league tables, fixtures, and stats.
OTB Player and Team Info — search ECF players, view your profile, manage teams, and save players in groups
Search ECF Players
Search by player name or ECF code. Results show ECF and FIDE ratings at a glance. Click a player to view their full rating history chart and recent game results, broken down by Standard and Rapid.
My Info
Claim your own ECF profile by searching for yourself and clicking “This is me”. Your profile card shows your current ECF and FIDE ratings with a quick-refresh button. Click your card to expand the full rating history and recent results.
Teams
Bookmark the teams you represent with links to their league pages, division standings, fixtures, and stats. Each team card provides one-tap access to league table and fixtures. Add a team avatar to personalise the card. Drag to reorder.
Saved Players
Save any ECF player to your library for quick access. Organise players into groups (e.g. by club or team). Each card shows current ratings across ECF and FIDE, with links to their official profiles. Players can also be linked to their online chess accounts from the Players tab, showing Lichess and Chess.com ratings alongside their OTB ratings. Use the filter toggles to show or hide ECF, FIDE, and Player Research data. Refresh all ratings in one click.
My Fixtures
Build a single chronological fixture list across every team you bookmark. Click Build My Fixtures, tick the teams to include (only teams with a saved fixtures URL are eligible), and the list is fetched from the LMS and merged into one table sorted by date. Each row shows the team, opponent, date, and home/away. Your team selection is saved to your profile and re-applied automatically next time you visit. The list refreshes from the LMS on each visit; if any team is served from cache (e.g. when the LMS is temporarily unreachable) you’ll see a “may be stale” banner with the cache age.
Subscribe in your calendar app: each fixture list has its own private iCal feed URL that you can paste into Google Calendar, Apple Calendar, or any other client to keep the fixtures in sync without re-visiting the page.
Captain Tools
If you captain a team, open Captain Tools from the OTB Players page to manage upcoming fixtures, build squads, and reach players quickly. Each fixture row has a status pill (e.g. “4/4 boards · 2✓ · 5–”) summarising squad fill and confirmed availability. Click a fixture to open the squad editor.
Fixtures — auto-imported from the LMS pages of the leagues you have configured. You can also add manual fixtures (date, opponent, home/away, notes) for events the LMS doesn’t cover.
Squad selection — add yourself, add saved players, drag rows to reorder boards, set per-player availability (Available / Tentative / Unavailable / Unknown) and free-text notes. Reserves sit below the boards.
Availability links — each candidate gets a unique tokenised URL the player can open without logging in. They tap Available / Tentative / Unavailable, optionally leave a note, and the captain’s view updates automatically.
Group emails — “Email all” or “Email unconfirmed” opens a single mailto: with all recipients in To, the captain in CC, and a pre-filled subject + match details body.
Per-player availability link emails — “Email availability links” lists each squad member with an “Open draft” button that creates a personal mailto: containing their unique link.
Copy summary — copies the squad in a tidy WhatsApp-friendly format.
My Info contact details — click the pencil button on your profile card to add an email address and phone number. These are used as the CC address on captain group emails and surface as tap-to-call / tap-to-WhatsApp icons throughout Saved Players and squad pickers.
Customise Layout
Use the “Reorder / hide sections” button at the top to rearrange or hide sections. Your layout preference is remembered across sessions.
Puzzles
Three types of tactical puzzles to sharpen your skills: opening/middlegame tactics, endgame puzzles, and checkmate puzzles. All sourced from real games on Lichess.
Opening puzzles — filter by opening, rating range, and track your solve stats
Puzzle Types
♞ Puzzles
General tactics from openings and middlegames. Find the best move or combination.
♖ Endgames
Endgame positions where precise technique is required to convert an advantage.
♕ Mates
Find the checkmate. Puzzles range from mate-in-one to longer mating sequences.
Endgame puzzles — rook, pawn, bishop, knight, queen, and mixed endingsCheckmate puzzles — mate in 2, 3, 4, or 5 moves
How It Works
Each puzzle shows the game context — the moves leading up to the critical position. Click “Start Puzzle” to begin solving. Make the correct move(s) on the board. The puzzle responds with the opponent’s moves until you’ve found the full solution. Use the “Hint” button if you’re stuck.
Game moves panel — replay the moves leading to the puzzle, then skip to the critical position
Rating Filter
Adjust the difficulty by filtering puzzles within a rating range. Each puzzle has a Lichess rating based on how difficult it has been for other players. You can also filter to only show puzzles from OTB master games (2550+ rated players).
Statistics & Retry
Your puzzle stats show how many you’ve attempted, solved, and your accuracy percentage. Failed puzzles can be retried — click “Retry Failed” to practice the ones you got wrong.
Engine Analysis
After completing a puzzle, toggle the engine to explore alternative solutions and understand why the puzzle move was best. Click “Analyse Game” to load the full game into the Analysis board.
Settings
Customise your experience — board appearance, piece style, account details, and data management.
Board appearance — choose from multiple colour themes and piece styles with a live preview
Board Appearance
Choose from multiple board colour themes and piece styles. A live preview shows exactly how the board will look. Changes apply across all boards in the app — analysis, puzzles, play, and books.
Engine Settings
Set the maximum search depth for the local Stockfish engine running in your browser. Lower depths use less CPU and battery — useful on mobile or when running on battery. Choose Unlimited for the deepest analysis. This only caps live engine analysis; the evaluation graph always uses depth 18 regardless of this setting, and cloud engine analysis (when available from Lichess) is unaffected.
Account
Update your display name (shown in bot matches and scoresheets), change your password, and upload a profile avatar.
Lichess API Token
Enter your Lichess API token to enable the opening explorer, which shows common moves and statistics from the Lichess database. The token is stored securely on your account.
Data Export & Import
Export all your data (games, players, settings, puzzle stats) as a JSON backup file. Import a previous backup to restore your data. Useful for migrating between devices or creating periodic backups.
Puzzle Stats
View your puzzle statistics for all three puzzle types — attempted, solved, and accuracy. Reset individual stats if you want a fresh start.
Digital Board Mode
If you use a digital chess board (such as the ChessNut Evo) that reads the screen position, add ?board=1 to the URL (e.g. icaruschess.org/?board=1) to enable Board Mode. This automatically disables engine arrows that can interfere with board recognition. The setting persists across sessions. To disable, visit with ?board=0. You can still toggle arrows manually with the A key.
Keyboard Shortcuts
Quick reference for all keyboard shortcuts across the app.
Analysis & Engine
←→
Navigate moves
Home
Go to start
End
Go to latest move
E
Toggle engine
F
Flip board
A
Toggle engine line arrows
S
Toggle last move highlight
Right-click board
Board display options (long-press on mobile)
↑↓
Move between games in live broadcast list
Puzzles
N
Next puzzle
H
Show hint
E
Toggle engine
←→
Step through moves
Home
Go to start
End
Go to puzzle position
Enter
Start puzzle
Books
←→
Previous / next page
↑↓
Previous / next move
Home / End
First / last page
F
Flip board
R
Reading mode
Space + drag
Pan the PDF page
Space + scroll wheel
Zoom in / out centred on cursor
Ctrl + scroll wheel
Zoom in / out (trackpad pinch equivalent)
Report a Bug
Found something that isn't working correctly? Let us know and we'll fix it.
Send notifications to all users. Messages appear in the notification bell and open as a modal when clicked.
Book Storage
League Configuration
Configure LMS organisation and event numbers for local leagues. These auto-populate URLs when users add teams, and can be bulk-updated when a new season starts.
New League
System Backup & Restore
Export the entire system database — all users, games, players, books metadata, puzzle stats, training plans, and settings — to a JSON file. Use this for disaster recovery or migration. Book PDF files are not included (back those up separately from the server filesystem).
System backup is ready. Download the file and store it safely.
Add Opening
User Management
Create New User
Save as Puzzle
Puzzle starts from this position:
All lines below are valid solutions — any of them counts as solving the puzzle.
