38

This calls for some scripting, so here's my first hasty attempt at it ;) Here's a quick way you can do the search on your own in python, using stockfish 10 and only the python-chess package. All open-source and free-software! Briefly, what the script will do: Consider all 960 positions, one at a time For each position, it scans over all legal white moves ...


24

If you're trying to make the strongest engine possible, absolutely go for NN engines. Traditional engines are great - Stockfish is arguably still the strongest engine on the planet on consensus equal hardware - but they are hard to write. These engines didn't get where they were overnight; they took years and years of work. Stockfish for example has been ...


19

If the engine can choose between getting mated in 2 or mated in 3, it'll choose the line where it is mated in 3 (even though the mate in 2 might be 'more difficult' to spot for humans). It can't really set traps, because it doesn't know what things might be difficult to spot for a human (or other engine) opponent. It just evaluates the position, without ...


15

Using @Phonon's Python script, I was able to determine that the worst move is 1. g4?? from the BBQRNNKR starting configuration, or 1. b4?? from its mirror image. This evaluates to -2.5 in one second of Stockfish search. Not quite a minor piece, but still a substantial handicap to recover from. Why is this position so powerful for the opponent? The black ...


13

In the beginning years of computer chess, people have actually tried to teach computers chess in the same way as they do with humans, explaining strategic concepts like a healthy pawn structure or the initiative. These attempt were soon abandoned because the method you describe was much more successful. Recently, there has been another attempt to let an ...


12

Stockfish assumes that all FEN positions you feed it are legal positions. If you feed it an illegal position and ask it to evaluate it, it will likely crash: Stockfish 5 64 by Tord Romstad, Marco Costalba and Joona Kiiski position fen 4k3/4p3/8/8/8/8/8/3KP3 go depth 14 Segmentation fault: 11 But you could use a Python library such as Chessnut to validate ...


12

Your "checkless" chess AI would run into problems with the stalemate rule. It would consider the poaition with white king on a6, white pawn a7, black king a8, a win for White because wherever Black moves his king it will get captured. In standard chess, of course, the position is a draw.


12

Threefold-repetition is about a position (not moves) occurring three times. Those positions do not have to be reached by the same moves. Also (as this also seems to be confused sometimes) it is completely irrelevant when this happens, e.g. you can have the same positions after moves 10, 42 and 63 and it would still be a draw. You should check whether the ...


12

A good chess engine won't stop after a predetermined number of moves, but will keep looking until the position is "quiescent", which roughly speaking means that there are no pending captures or checks. See Quiescence Search in chessprogramming wikispaces for a more detailed explanation.


11

Let's use Stockfish to find out the moves for this position [fen "N7/P3pk1p/3p2p1/r4p2/8/4b2B/4P1KP/1R6 w - - 0 34"] The FEN string is: "N7/P3pk1p/3p2p1/r4p2/8/4b2B/4P1KP/1R6 w - - 0 34". You should copy-and-paste my commands to experience yourself. Load the position by "position fen ..." and then use "d" to print the position. Please note that "d" is a ...


10

PyChess Is a chess client built in Python. You can use it's chess logic libraries without much trouble. http://code.google.com/p/pychess/source/browse/utilities/arena.py http://code.google.com/p/pychess/source/browse/utilities/blunders.py Are examples of how you you might use the libraries to control chess engines, but you can also use just the chess ...


10

There're only two protocols - UCI and Winboard. Winboard is an old protocol and not really being used nowadays. Crafty is the only major engine still supporting the Winboard protocol, but it's only because the engine is also very old. UCI is a newer protocol developed by Shredder, and is used everywhere - Windows, Macs, Linux, Android, iOS etc. UCI is really ...


9

Easy question. Announce your engine on the chess programming forum (http://talkchess.com/forum/index.php). There'll be engine testers adding your engine to their rating list, such as CCRL. But please and please provide a working compiled binary. Announce your engine, upload a compiled binary to somewhere like Dropbox. You'll hear feedback. EDIT cutechess ...


9

Maybe you can take a look at TalkChess, a forum dedicated to computer chess. I found a recent thread that might be interesting for you: Progress in 30 years by four intervals of 7-8 years A couple of matches between (former) top engines are played on the same hardware. The test suggests that in the recent years (2002-2017), the gain is mainly made by ...


9

So, in terms of creating the strongest chess engine possible, should I go neural network or hard-coded? Don't choose a NN unless you have access to ridiculous(A few hundred Nvidia V100s). Training a NN to play chess takes so much hardware. See the people contributing to Lc0 to train over 200 million games. Since you will probably have trouble accessing the ...


8

Would this be what you are looking for? PGN-extract (A command line utility) http://www.cs.kent.ac.uk/people/staff/djb/pgn-extract/ I can see a flag in the feature doc that might help: -W[cm|epd|halg|lalg|elalg|san|uci] - specify the output format to use -Whalg is hyphenated long algebraic. -Wlalg is long algebraic -Welalg[PNBRQK] is enhanced long ...


8

Computer detection of dead positions is much trickier than people think. It is unlikely that an algorithm exists that runs in reasonable time and is 100% accurate. It is easy to check for a simple condition like insufficient material (K+B v K, K+N v K). It is less easy to check for cases with blocked pawns, for instance: 2b1k3/8/8/1p1p1p1p/1P1P1P1P/8/8/...


8

First step: Define your goals/reasons I think this is the predominant factor. Which of these best fits you? (Choose only one) You want to enjoy a fun, challenging coding task You want to create an extremely good chess engine You want to learn about how chess engines work You want to learn/practice coding skills You want to learn/implement computer science ...


8

Thanks for your compliment about pgn-extract (I am its author). You might be able to make the task a little easier by adding --linelength 1000 to the argument list in order to get each game on a single line, then use sed to add an unknown result to the end of the game and re-process the game with pgn-extract to add an empty 7-tag roster. Finally, use sed ...


7

What you're looking for is a PGN file that contains several games. You can parse the game data and enter in the opening moves. A great resource is PGN Mentor where you can browse openings and download the appropriate PGNs.


7

The Chess Programming Wiki is a good place to start . As you will quickly find out, it's a rather large and complex problem space, with many challenges (conceptual as well as actual programming). There are plenty of open source engines out there which you could look at, to learn, or even to integrate into your engine. I think you'll generally find that ...


7

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 clarifications or possible extensions of the code: To showcase a working example, I've taken a game between Adams and Kasparov, you can download the PGN from the ...


7

You seem to be writing a move generator. Conventionally, a set of legal moves is generated by first generating a list of pseudo-legal moves (i.e. all moves which could be made, ignoring the fact that the king needs special treatment) and then filtering out moves which leave the king in check. The legal move generator in Stockfish (one of the strongest ...


7

The other answer is wrong; we can in fact program the chess engine to favour traps! As you already noted, when the engine thinks it is winning it should simply choose the best move. So the question is how to aim for the sharpest lines for the opponent when it is losing. This is of course subjective, and depends on the kind of opponent we are pitting it ...


6

This is not a direct answer to your question — but because you're interested in Java, check out this link, which has a UCI compatible engine written in Java. Browsing through the code it looked quite readable. It loses to Crafty and Stockfish regularly, but that is to be expected — they usually looked ~4 ply deeper because of the speed difference. I think ...


6

If I were going to do this, I'd choose Stockfish, Fruit 2.1, and Crafty for no reason other than their high quality is proven. Then I'd compare and contrast the techniques, algorithms, and choices made by each. These aren't easy programs; it would be a lot of work to gain a true understanding.


6

Take a look at the C# port of Stockfish by bpfliegel. To my knowledge it is complete (was able to compile and run it) and even though it has not been updated in 11 months at the time of this post it is certainly much stronger than the other engines listed. When I tested its perft function it on my machine it was only a factor of 1.5 slower than the original ...


6

There is a detailed standard of PGN available, for instance here: PGN standard at the Wayback Machine. You will never see "e4 e6 f4" in a PGN file, since it is mandatory to mention the move number before white's move: "1.e4 e6 2.f4".


6

As others have said, UCI is the API you want. The full specifications of the protocol is here (the zip file extracts to a text file): http://download.shredderchess.com/div/uci.zip It's actually very straight forward and simple, a UCI engine must respond to and reply in plain text through stdin, stdout and stderr. In fact, you should be able to launch the ...


6

It may depend a little on what your code can access, but either way you should read Ed Schröder's pages on this topic. Schröder was the author of the Rebel Chess software until his retirement about a decade ago. In the '90s Rebel was the strongest consumer/commercial chess software and the first such to beat a GM (Anand). Since retiring he turned Rebel ...


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