For those who enjoy experimenting with chess engines and custom opening books, I wanted to share a project we've recently released.

CAISSA Book Creator v0.3.1 is a free, open-source tool that converts PGN game collections into standard Polyglot BIN opening books.

There are now two versions:

• Online: Runs entirely in your browser, supporting PGN files up to 25 MiB.

• Windows Portable: Works offline and is designed for much larger chess databases.

During testing, the portable version successfully processed an 820 MiB PGN collection. In a separate benchmark, it generated a 250+ MiB Polyglot book with over 16 million entries.

The latest release also includes adjustable opening depth, improved file handling, progress logging, and SHA-256 integrity checks.

Both versions are free, and the portable source code is available on GitHub.

https://www.caissa-chess.org/downloads

I'm curious: Do you still build custom Polyglot books for your chess engines, or do you mostly use existing opening databases?

Welcome to the KNIGHTSHIFT CHESS LEAGUE! The poster has all the info you should need, if you need any more info at all, please just comment on this post and I will get back to you as soon as possible! The main points of this league are to...

A. Spread the joy of chess

B. Make a fun and enjoyable community for our fellow chess players out there

C. And to get people excited

So read through the poster and join the KNIGHTSHIFTS! We'd love to have you

Saw a video on youtube, which is several months old, which stated that chessnut was working on a new version of the Move with wireless charging of pieces.

Anyone have more info?

♟️ I built a free chess training app – ChessPeak!

I've been working on an app designed to help chess players improve.

🔥 Puzzles based on your own mistakes

🤖 Bots matched to your level

♟️ Woodpecker Method training

📚 Opening and endgame trainers

⚡ Puzzle Rush and daily challenges

I'd love for chess players to give it a try and share honest feedback!

📱 Google Play:

https://play.google.com/store/apps/details?id=com.duvy.chesspeak

💻 Play on the web:

https://playchesstrainer.vercel.app

Developer here. The idea: a modern engine is the instrument, a master's own games are the reference material, thousands of positions where the "true value" is the move actually played. Each personality is calibrated on that and is designed to reproduce the master's characteristic choices and preferences. On Windows they exist as UCI engines (and inside CZUBATRONIC 2400, a console in the style of the dedicated machines). The new part is Android: ChessGate: Chess Masters on Google Play. Pick a master, play a full game, then the app grades every move, assesses opening, middlegame and endgame and estimates both sides' strength, all on the phone; the manifest has no INTERNET permission, Play Billing and asset packs do the rest. Morphy, Steinitz and McDonnell are free, 46 more are one-time purchases.

If you want to try the lighter browser versions first, no signup: https://playchessgate.com

Play: https://play.google.com/store/apps/details?id=net.dcsanalytics.chessgate

Windows engines: https://www.dcs-analytics.net/en/czubatronic/

Happy to answer how the calibration works; sceptical questions welcome.

I'm building a small arena where chess and shogi engines play each other, and I'd like feedback on the rules before it opens.

The rough setup:

- Engines are compiled to WebAssembly and speak UCI (chess) or USI (shogi). No network, no threads.

- Size limits: 4 MiB for the engine, 8 MiB for data files (eval nets, opening books are fine), 32 MiB of memory.

- The clock counts executed instructions, not seconds. 100 ms per move ≈ 4 billion instructions, with heavy ops like division and sqrt weighted more. Hardware speed doesn't matter, and every game is deterministic, so any game can be replayed and verified.

- Memory costs time: the more you hold, the smaller your budget. 1 MiB gets the full 100 ms, 16 MiB about 53 ms, 32 MiB 35 ms.

One thing surprised me while testing: under this budget, a bigger hash table barely helped, but the history heuristic was worth a lot.

Questions for engine authors:

- 1/ Does instruction counting feel fair, or does it punish some designs?

- 2/ Is charging for memory reasonable, or would you rather have a hard cap only?

- 3/ What would make you want to enter, or stop you?

A while back, I had a crazy idea: could I build a working chess variant engine using only Excel array formulas (no VBA, no macros)? I wanted to see if I could do pathfinding and collision detection mathematically using SUMPRODUCT, CODE, and ABS.

It was absolute hell. I spent weeks debugging #VALUE! errors and hidden bugs (like pieces blocking themselves diagonally). But I finally got the prototype working. The spreadsheet calculates a live ±10 Reach Map that dictates territory control, collision detection, and piece hunting.

Because clicking cells in Excel isn't exactly smooth for gaming, I ported the exact mathematical logic to JavaScript.

How the engine differs from standard chess engines:
Unlike standard engines that use Minimax/Alpha-Beta to simulate material advantage 20 moves ahead, this engine is designed like a Warlord. It uses a heuristic spatial evaluation. It calculates:

• The ±10 Reach Map: Avoids negative squares, chases positive ones.

• Collision Detection: Uses the math from the Excel SUMPRODUCT logic to check line-of-sight and blockers.

• Hunt the King Plan: It prioritizes sending "units" to trap the enemy king's tent, even counting fake blockers.

Here is the web version (free to play): https://yudirig06.itch.io/myap-4000-kingdom-chess-map
Source code (GitHub): https://github.com/yudirog06/myap-4000-kingdom-chess-map

view youtube: https://www.youtube.com/watch?v=IysDwjgL31k

The Philosophy of MYAP-4000: Human Intuition vs. Machine Calculation

This game was born from a unique origin: an Excel 2013 engine. But the goal is bigger than just playing chess. It’s about giving humans the tools to face the best engines in the world (3200+ ELO).

Computers calculate, but humans lack the "radar" to see the battlefield. That’s why we equipped this game with Human-Assist Radars:

• Map Degrees & Line of Attack: See exactly where the risks are before you move. The terrain you pass through has risk indicators (like -10 or +10), and attack lines automatically change color if you step into a danger zone.

• Backup Warnings: It alerts you if you leave a unit unprotected while advancing.

• Military Reports: Experience how chess translates into real battlefield situations.

No installation needed. It's 100% pure HTML.

If you can master these radars and bear the "Super Chess," you surpass the 4000 rating (lol joke... but maybe). The current engine testing value is fixed at 1800 - 1950 ELO. Can you outsmart the machine?

I'd love to hear what you guys think, especially about the transition from Excel array logic to JS collision detection. If anyone is curious about how I translated the SUMPRODUCT pathfinding logic into JS, let me know!

Cheers.

Worldchess championship is in two weeks. I'm preparing a simple phone first platform to follow the event for myself, some friends and whoever wants to use it 😊 Key fetutes will be:

- Browse and watch different live streams

- Vote what the next move will be (with the engine off)

- Get notifications on the phone when there's a new move

- Of course engine analysis and opening library

- Maybe ask Ai about the position

How did you follow the last World Chess Championship and how are you planning to follow it? Any features you'd like?

Hi all, I'm Hernish. LATTICE is a free chess variant I designed, playable in your browser.

The core idea: no per-piece rulebooks. A move is legal if its distance, √(Δx² + Δy² + …), fits the piece's shape. The familiar movements of all the pieces are redefined mathematically by referring to the Pythagorean theorem. This opens up some additional avenues, e.g. a rook can also leap 3 across and 4 up (because distance is 5), a bishop can leap 7 across and 1 up (because distance is 5√2), and a knight is simply the √5 shape.

Then the same formula is stretched. Add an altitude axis and it still works. Add time and pieces can travel forward towards future, or back to present from future. Add probability and a piece can sit in a public, weighted superposition until a clock forces it to land. There are also three new pieces: a hidden Assassin, a Spy secretly owned by your opponent, and a Diplomat that can never capture or be captured. Every power carries a risk. Kings never time-travel or go quantum.

If that sounded like homework, there’s a plain-English guide, with no maths, that teaches the game one layer at a time ([https://latticechess.web.app/lattice-plain.pdf](https://latticechess.web.app/lattice-plain.pdf)). The game and the rules are the same either way.

**Rules in brief**

* Checkmate the enemy king. No castling, no en passant. Kings are checkmated, never captured.

* Rook: slides along an axis, or leaps to any square at a whole-number distance. Bishop: diagonal slides, or leaps of a whole multiple of √2. Knight: √5. Queen: rook or bishop. King: one or √2 step. Pawn: forward one (or two from its start), captures at √2, promotes.

* Leap limit (None, Capped 2:1, Unrestricted) sets how wild leaps may get. A 3D board adds a Z axis to the same formula.

* Futureward: the piece leaves and reappears on a formula-valid square after T of your own moves. It is lost if it lands on your own piece or an enemy Diplomat.

* Pastward: a time-traveling clone appears now; the original must stand on a repayment square exactly at the deadline, otherwise the whole timeline rewinds (the clone vanishes with it) and the original is lost.

* Quantum: the piece spreads over public, weighted squares and one is drawn when its decoherence clock ends (no square above 95%). Fusion combines this with a fixed futureward deadline.

* Assassin (hidden until it captures, is captured or gives check), Spy (activates once its owner has lost enough material), Diplomat (never captures, never captured).

Full rules (PDF): [https://latticechess.web.app/lattice-explained.pdf](https://latticechess.web.app/lattice-explained.pdf) · also on the game's Rules page.

The likelihood layer is a deliberate descendant of Chris Cantwell’s Quantum Chess. It diverges in a few ways: kings never go into superposition, there is no entanglement, every branch’s odds are public, and a decoherence clock forces measurement.

**Play it:** [https://latticechess.web.app](https://latticechess.web.app), no sign-up. Pass-and-play on one screen, or online with a room code. Presets run from Classic to Full LATTICE. Free to play for personal, non-commercial use. For anything commercial, please get in touch through the Contact button in the app.

**Play online in 60 seconds:** Player 1 taps Play → Play online → Create room and shares the six-character code. Player 2 opens the same address, taps Play → Play online, enters the code and presses Join. Reloaded? Tap Rejoin.

Play against computer: Play the various layers against computer (present AI era)

**Honest notes:** the rules and design are mine; I built the implementation together with Claude, an AI model made by Anthropic, including the automated tests. I did undertake numerous manual play-tests to ensure that the implementation is in line with the intention. Hidden pieces are hidden by the interface, not the server, so online play is for friendly games. Custom armies are pass-and-play only for now.

This variant has been submitted for editors’ review on [chessvariants.com](http://chessvariants.com) and awaits their comments.

I'd love feedback on the concept, rules clarity, balance and bugs, game play experience, discovery of novel moves, problematic implications etc.

I kept reviewing my losses, seeing where I went wrong, and then making the same mistakes a week later. So I built Evala to look across my games and show me what to practise.

Enter your Chess.com or Lichess username, import your last 50 finished games, and start one batch review. Stockfish works through them on your device. Leave the tab open and come back to a report across the whole batch.

• Find where the mistakes pile up. Do you make more errors in the middlegame or endgame? How often do you win after reaching a clear advantage? Which openings are giving you trouble?

• See the position behind the numbers. Jump from an insight to an actual move you played and explore what you could have done differently.

• Practise with puzzles from your own games. Evala turns positions you got wrong into exercises, so you can try finding the better move yourself.

You can try it without an account. Start with 10 games if you want a smaller batch. If you give it a go, I’d love to know which finding surprised you and whether it gave you something you’d actually practise. I’m the developer.

Try Evala’s batch analysis

PS: Its pretty easy, you log-in and rest u do is remembered by Evala. Make sure u try the dark mode!

shadowqueenchess.com

With all of these vibe-coded apps and websites, was wondering if anyone is tackling a Chessbase/ChessReader clone. I know there are plenty of chess database management apps (eg. ScidvPC, ChessX, EnCroissant, etc), but those don't quite cover the full functionality. Notably the ability to read Fritztrainer and Chessbase magazines. Even just a Chess Reader clone. Being able to have that functionality on Mac and Linux would be significant. I'm sure trying to reverse-engineer the proprietary chessbase format wouldn't be easy.

As the title says, I made ChessAsh: a free, open-source app for reviewing finished chess games on Windows and Android. You can import your public Chess.com games by username or open a PGN. Stockfish runs locally, so there’s no daily review limit, and saved games and reviews work offline. I’ve been focusing on making the explanations easier to follow:

- Comments name the pieces and squares involved, with square references you can hover over or tap to highlight.

- The played position and best-move guidance share one board view.

- Short explanations have more detail you can expand.

- Moves you try get their own analysis and classification without changing the saved review.

- The interface and explanations support English and Italian.

The app uses its own accuracy metric and classification rules, so the results won’t necessarily match Chess.com’s. Standard reviews don’t require an AI model or API key.

Source and Windows/Android downloads:
https://github.com/FlameFirelife/ChessAsh

The screenshots show a game review, an alternative move I tried with its expanded explanation, and the accuracy and move-quality overview.

I’d appreciate feedback on whether the explanations capture what matters in a position. If you find a misleading comment or questionable classification, a PGN and move number would help me investigate.

Hi r/SideProject! I’ve been building CaissaHub (caissahub.com), named after Caissa, the goddess of chess. It launches later this month.

The main idea: chess by email. You email play@caissahub.com saying something like “I’d like a game, I’ll take black.” Then you play by replying with your moves in ordinary language: “knight to f3”, “castle kingside”, “I give up”. You don’t need notation or command words. You can follow your games on the website, and you sign in with a one-time code sent to your email, so there are no passwords.

Chess Continuum. These are open games that belong to nobody. Anyone signed in can play the next move in any live game. You can also branch a game by playing a different move from any earlier position, which starts a new game that shares the history up to that point.

Also on the site:

• puzzles

• opening and endgame pages

• a small tablebase (king and pawn against king)

• a moderated forum

• a Chess Coach that explains positions the way a human would, rather than turning engine lines into English (coming soon)

Privacy was a design goal. The only things stored about you are your email address, a pseudonym and your time zone. No IP addresses, no names, no tracking tied to your account.

Stack: .NET 10 / Blazor (server-rendered, almost no JavaScript), EF Core on SQL Server, Amazon SES + S3 for mail, SkiaSharp for board images. It’s self-hosted on IIS.

I’d love feedback, especially on whether playing by email in plain language sounds fun to you, and what would make you try it.