Hot answers tagged

15 votes
Accepted

High-quality (not bitmap) diagram software

As thb pointed out, you need vectors. I suggest you use a python-chess to generate SVG vector images. Prerequisites: Python 2.6+ or 3.3+ Python-chess: Install form pypi using pip: pip install ...
user avatar
  • 368
11 votes
Accepted

Stockfish evaluation of a position from PGN

Yes there are easy ways to do this. I'm going to briefly show you one quick way of doing it in python, using the python-chess module. If the in-code comments are not enough, feel free to ask for ...
user avatar
  • 11.8k
10 votes
Accepted

Longest possible FEN

The FEN consists of six parts (see definition of FEN here): piece placement: at most 64 characters, one for each square plus 7 times "/" to delimit ranks = 71 characters active color: one character ("...
user avatar
  • 20.4k
9 votes
Accepted

What's the point of the full move counter in FEN?

You may want to record a fragment of a real game starting from move number 24, for example. Then you specify the FEN after the first 23 moves and set the full move number to 24.
user avatar
7 votes

How can I scan a chessboard and obtain its FEN?

This website has a chess ebook reader available for scanning chess diagrams from PDF: https://chessvision.ai/ Additionally they also have browser extensions for Chrome and Firefox which is really ...
user avatar
  • 357
7 votes

How can I scan a chessboard and obtain its FEN?

I wrote a program that can recognize positions from books and magazines and give you the FEN. Here is the web interface for Chessputzer You can upload the image or paste directly from the ...
user avatar
  • 239
7 votes
Accepted

Software to create FEN notation?

I am looking for a software or web site, which allows me to place the pieces on the board, and then create FEN notation automatically. I personally use this site for that. It is free, and it is an ...
user avatar
6 votes

Do better board representations than the standard one exist?

Chess is a game in two dimensions. The game is made to be played in two dimensions. Pieces move horizontally, vertically, and diagonally very naturally on a chess board. It's purely visual and the ...
user avatar
  • 19.9k
6 votes
Accepted

Alternatives to the FEN notation

Since you're talking about programming, you're presumably looking for a storage scheme more compact in computer memory space than FEN. Besides going out to research how it's done in large tablebases, ...
user avatar
  • 2,113
5 votes

How do you know when a FEN position is legal?

For the others, there is a simple function in Stockfish engine, that validates a FEN String. bool Position::is_valid_fen(const std::string &fen) { std::istringstream iss(fen); std::string ...
user avatar
5 votes

How can I scan a chessboard and obtain its FEN?

Chessfimee can perfectly serve you. It scans and analyses chessboards with chess diagrams, puzzles. All you need is to use the camera to take a photo of a chess diagram from books, papers, even LCD ...
user avatar
5 votes
Accepted

How does X-FEN (Chess960 FEN) differentiate from traditional FEN notation?

Let's start at the beginning To understand X-FEN for castling in Chess960, it helps if you first understand castling in Chess960. Castling rules are slightly different in Chess960, hence there comes a ...
user avatar
5 votes

Chess Problem Database with PGN or FEN

http://gorgonian.weebly.com/pgn.html http://exeterchessclub.org.uk/downloads (in chessbase format) Exeter has many other valuable resources.
user avatar
  • 3,072
5 votes

How can I convert screenshot capture into FEN to analyse on Windows 10+?

This will do it. https://chessvision.ai. There is also the Chessify app on the ios store where you can take pictures of chessboards and import the position.
user avatar
  • 51
5 votes

Longest possible FEN

Using the definition of FEN it is relatively straightforward to compute an upper bound: piece placement: 64 (pieces/squares) + 7 (slashes) color: 1 (w/b) castling: 4 (KQkq) en passant: 2 (e3) ...
user avatar
5 votes
Accepted

Programming FEN diagrams

You can make use of the online fen2png.com site, calling it with wget or curl: curl 'https://fen2png.com/api/?fen=r1b1k1nr/p2p1ppp/n2B4/1p1NPN1P/6P1/3P1Q2/P1P1K3/q5b1%20w%20kq%20-%20-&raw=true' &...
user avatar
4 votes

How can I scan a chessboard and obtain its FEN?

Try the following. You upload the image, it scans and generates FEN. I don't know if it will read a pdf but converting a pdf to a common graphic format is not hard. Chess Grabber I tried it using ...
user avatar
  • 19.9k
4 votes

High-quality (not bitmap) diagram software

My solution has been to use a chess font like Chess Merida or Chess Cases. With such a font for example the start position is written like this: 1222222223 4tMvWlVmT5 4OoOoOoOo5 4 + + + +5 4+ + + + 5 ...
user avatar
4 votes

How do you know when a FEN position is legal?

Coming to the party late. Firstly I do not think it’s possible to validate 100% that a position is legal as the questioners asks. There are tens of thousands of retroanalytic problems which dance ...
user avatar
  • 9,458
4 votes

High-quality (not bitmap) diagram software

A vector format would suit. As you may know, a vector format represents graphic not as a bitmap but geometrically, as a mathematical description which can be rendered at any scale. For web display, ...
user avatar
  • 4,431
4 votes

How do you know when a FEN position is legal?

There is nothing in the FEN specification saying that the represented position must be reachable from the initial array. Proving that a given position is reachable from the initial array is an ...
user avatar
4 votes

Numerical FEN writing

If all the pieces are on the board, there are 64!/32!/8!^2/2^6*(32/63)*(31/61) or about 1.2*10^42 positions. This would require 140 bits. The 64!/32! puts the pieces on squares, the divisions ...
user avatar
4 votes

How the engine can detect the 3-fold repetition using FEN input?

https://en.wikipedia.org/wiki/Forsyth%E2%80%93Edwards_Notation "FEN does not represent sufficient information to decide whether a draw by threefold repetition may be legally claimed or a draw offer ...
user avatar
  • 1,696
4 votes
Accepted

Why is en passant possibility recorded in FEN regardless of whether there is a pawn ready to make the capture?

Easier for everybody. No need to check enpassant possibility.
user avatar
  • 21.6k
4 votes

What's the point of the full move counter in FEN?

One rule that depends on the move count is the time control. If you have a time control of 40/120, you need to know which move it is to know when the players get more time.
user avatar
  • 15.6k
4 votes

How can I convert screenshot capture into FEN to analyse on Windows 10+?

https://www.ocf.berkeley.edu/~abhishek/putz/ Lost two piece from scan http://www.chessgrabber.nicolaas.net/ Lost one piece, added one piece, and replaced two pieces. https://play.google.com/...
user avatar
  • 5,131
4 votes
Accepted

Software for reading multiple FEN positions

A file that contains one FEN per line is a file format in itself. It's the file format used by test positions for chess engines. So engines definitely have some process to analyse all the positions in ...
user avatar
  • 1,969
3 votes

Software to create FEN notation?

SCID will do it. Create a position using Edit->Setup Board. There's a text box at the bottom of the setup window with the FEN. Or, if you've been playing against the computer, you can just say ...
user avatar
  • 19.9k
3 votes

Software to create FEN notation?

I use the Lichess Board editor. It has drag and drop, and click and place and it provides the FEN to any position.
user avatar

Only top scored, non community-wiki answers of a minimum length are eligible