5 ms·

Micro-Max, a 133-line Chess Source

137 points by mocy 5y ago

mocy 5y ago
Surprisingly good chess engine (ELO ~2000). Good resource for my kids, the younger learning chess and the older interested in programing.
mocy 5y ago
on iOS, Chess Mini is build around Micro-Max: https://apps.apple.com/us/app/chess-mini/id616424231 https://apps.apple.com/us/app/chess-mini/id616424231
- tasty_freeze 5y ago
  Despite the engine being 2000 chars and 133 lines, the GUI is expensive. From the program description: Size 40.5 MB
  - deleted 5y ago
    [deleted]
tromp 5y ago
An interesting long running (2009-2021) discussion between H.G. Muller, author of Micro-Nax, and Oscar Toledo Gutiérrez, author of competing minimal chess program (and IOCCC winner [1]) nanochess, may be found on the chess programming forum [2]. [1] https://en.wikipedia.org/wiki/International_Obfuscated_C_Code_Contest#Toledo_Nanochess https://en.wikipedia.org/wiki/International_Obfuscated_C_Cod... [2] http://talkchess.com/forum3/viewtopic.php?f=7&t=26622 http://talkchess.com/forum3/viewtopic.php?f=7&t=26622
spicybright 5y ago
I didn't think this was much, just some kind of chess rules engine, but this program also implements an AI opponent to play against. That's insanely impressive!
- actually_a_dog 5y ago
  Not just “an” AI opponent, either, but a fairly sophisticated one. https://www.chessprogramming.org/Alpha-Beta https://www.chessprogramming.org/Alpha-Beta https://www.chessprogramming.org/Quiescence_Search https://www.chessprogramming.org/Quiescence_Search
jfoucher 5y ago
This is nice, I just compiled it, but how do I play it? I can't seem to find any instructions on the website...
- jkingsman 5y ago
  From https://home.hccnet.nl/h.g.muller/download.html https://home.hccnet.nl/h.g.muller/download.html: > To play you must enter moves in algebraic notation, and to make the computer do a move you should press an extra enter. You can alternate sides whenever you want, the program accepts or plays moves for the side whose turn it is to move. After having done a move, be it yours or his own, micro-Max prints a board with the new position. To quit type control-c.
- deleted 5y ago
  [deleted]
- racingmars 5y ago
  The instructions say you must enter "algebraic notation," but I couldn't figure it out until I took a peek at the source code to see how it was trying to parse input. You always just enter source square to destination square. So to play an opening move 1. d4, you would type `d2d4` (move piece on d2 to d4) and press enter. Then if you want micromax to play the next move for black, just press enter again. It'll think for quite a while and draw the board with the new position. To play 2. Bf4, you'd then type 'c1f4', and so on. (This appears to be "long algebraic notation" and is apparently common in chess engines, now that I look it up on Wikipedia.)
  - jfoucher 5y ago
    Right, that's the answer. I tried using regular algebraic notation without success, but this works fine. Thank you.
actually_a_dog 5y ago
If you find this interesting, the Chess Programming Wiki has a real treasure trove of info on computer chess. https://www.chessprogramming.org/Main_Page https://www.chessprogramming.org/Main_Page
TheOtherHobbes 5y ago
A reminder that in 1982 you could buy "1K ZX Chess" for the Sinclair ZX81. It ran in 672 bytes of Z80 machine code, including graphics. (Unfortunately a few features had to be left out. But still.)
- classichasclass 5y ago
  6502 MicroChess says hi. http://www.benlo.com/microchess/index.html http://www.benlo.com/microchess/index.html
femto113 5y ago
> Except for under-promotions ... since the program is unlikely to ever find itself in a situation where it would be useful to play one. Not my proudest moment but I did cheese out a tie in an otherwise lost game in jr. high by moving into what would be a stalemate if opp naively queened his pawn. It was extra ugly because he moved, picked up his previously captured queen from the side of the board, put it down, but didn't take his hand off of the queen before realizing the mistake (literally any other piece would have given him a clear win). Had to get a ruling on whether he was committed, judge decided it was too late because he'd taken his hand off the pawn (I have no idea what the official rule is in this scenario). I still regret not just resigning, but 12 year old me could be a jerk sometimes.
- cmeacham98 5y ago
  The judge is right for the wrong reason: https://chess.stackexchange.com/questions/32495/is-there-a-touch-promote-rule https://chess.stackexchange.com/questions/32495/is-there-a-t... The promotion is committed as soon as the new piece touches the promotion square.
- Aditya_Garg 5y ago
  Don’t feel too bad. Learning how to watch for stalemate tricks when you’re winning is a very important chess lesson. Look up Eric Rosen stalemate traps on YouTube. This is an IM who regularly tricks GMs into stalemate. The GMs are not mad at him, only themselves for falling for it.
- Bootvis 5y ago
  Swindling is part of the game at all levels. Personally, I feel good about it even at 35 as long as I followed the rules. I remember a kid changing the colour of his bishop by 'misplacing' it on a different colour square to get the same colour in a bishop-pawn endgame. That was not OK.
selcuka 5y ago
There's also The Kilobyte's Gambit [1], which is a chess engine written in 1024 bytes of JavaScript. [1] https://vole.wtf/kilobytes-gambit/ https://vole.wtf/kilobytes-gambit/
xwdv 5y ago
Why bother implementing rules at all? Just create an interface to move pieces around on a board wherever you want. If you play chess you should know the rules and how to move pieces.
- greyman 5y ago
  I kind of agree, chess without promotions, castling and en passant is not chess. But the guy also made full version, with impressively small size: For real purists: a close-to-minimal version that does understand full FIDE rules including under-promotion can be found here. It measures 1433 characters. (although I don't know why people who adhere to chess rules are called "purists", but whatever. :-))
  - xwdv 5y ago
    In Ultima Online we would play chess to pass time on long sea voyages while hunting for monsters or treasure. There was no rules engine, it was just a simple board where you could drag and drop pieces around on any which way, which allowed for a lot of flexibility in how you played. We could even play random chess this way.
thom 5y ago
Don't know if the author frequents these parts, but I really enjoyed the annotated Toledo chess source book, and would very happily pay for similar here!

137 points by mocy 5y ago

mocy 5y ago

Surprisingly good chess engine (ELO ~2000). Good resource for my kids, the younger learning chess and the older interested in programing.

mocy 5y ago

on iOS, Chess Mini is build around Micro-Max: https://apps.apple.com/us/app/chess-mini/id616424231 https://apps.apple.com/us/app/chess-mini/id616424231

tasty_freeze 5y ago
Despite the engine being 2000 chars and 133 lines, the GUI is expensive. From the program description: Size 40.5 MB
- deleted 5y ago
  [deleted]

tromp 5y ago

An interesting long running (2009-2021) discussion between H.G. Muller, author of Micro-Nax, and Oscar Toledo Gutiérrez, author of competing minimal chess program (and IOCCC winner [1]) nanochess, may be found on the chess programming forum [2]. [1] https://en.wikipedia.org/wiki/International_Obfuscated_C_Code_Contest#Toledo_Nanochess https://en.wikipedia.org/wiki/International_Obfuscated_C_Cod... [2] http://talkchess.com/forum3/viewtopic.php?f=7&t=26622 http://talkchess.com/forum3/viewtopic.php?f=7&t=26622

spicybright 5y ago

I didn't think this was much, just some kind of chess rules engine, but this program also implements an AI opponent to play against. That's insanely impressive!

actually_a_dog 5y ago
Not just “an” AI opponent, either, but a fairly sophisticated one. https://www.chessprogramming.org/Alpha-Beta https://www.chessprogramming.org/Alpha-Beta https://www.chessprogramming.org/Quiescence_Search https://www.chessprogramming.org/Quiescence_Search

jfoucher 5y ago

This is nice, I just compiled it, but how do I play it? I can't seem to find any instructions on the website...

jkingsman 5y ago
From https://home.hccnet.nl/h.g.muller/download.html https://home.hccnet.nl/h.g.muller/download.html: > To play you must enter moves in algebraic notation, and to make the computer do a move you should press an extra enter. You can alternate sides whenever you want, the program accepts or plays moves for the side whose turn it is to move. After having done a move, be it yours or his own, micro-Max prints a board with the new position. To quit type control-c.
deleted 5y ago
[deleted]
racingmars 5y ago
The instructions say you must enter "algebraic notation," but I couldn't figure it out until I took a peek at the source code to see how it was trying to parse input. You always just enter source square to destination square. So to play an opening move 1. d4, you would type `d2d4` (move piece on d2 to d4) and press enter. Then if you want micromax to play the next move for black, just press enter again. It'll think for quite a while and draw the board with the new position. To play 2. Bf4, you'd then type 'c1f4', and so on. (This appears to be "long algebraic notation" and is apparently common in chess engines, now that I look it up on Wikipedia.)
- jfoucher 5y ago
  Right, that's the answer. I tried using regular algebraic notation without success, but this works fine. Thank you.

actually_a_dog 5y ago

If you find this interesting, the Chess Programming Wiki has a real treasure trove of info on computer chess. https://www.chessprogramming.org/Main_Page https://www.chessprogramming.org/Main_Page

TheOtherHobbes 5y ago

A reminder that in 1982 you could buy "1K ZX Chess" for the Sinclair ZX81. It ran in 672 bytes of Z80 machine code, including graphics. (Unfortunately a few features had to be left out. But still.)

classichasclass 5y ago
6502 MicroChess says hi. http://www.benlo.com/microchess/index.html http://www.benlo.com/microchess/index.html

femto113 5y ago

> Except for under-promotions ... since the program is unlikely to ever find itself in a situation where it would be useful to play one. Not my proudest moment but I did cheese out a tie in an otherwise lost game in jr. high by moving into what would be a stalemate if opp naively queened his pawn. It was extra ugly because he moved, picked up his previously captured queen from the side of the board, put it down, but didn't take his hand off of the queen before realizing the mistake (literally any other piece would have given him a clear win). Had to get a ruling on whether he was committed, judge decided it was too late because he'd taken his hand off the pawn (I have no idea what the official rule is in this scenario). I still regret not just resigning, but 12 year old me could be a jerk sometimes.

cmeacham98 5y ago
The judge is right for the wrong reason: https://chess.stackexchange.com/questions/32495/is-there-a-touch-promote-rule https://chess.stackexchange.com/questions/32495/is-there-a-t... The promotion is committed as soon as the new piece touches the promotion square.
Aditya_Garg 5y ago
Don’t feel too bad. Learning how to watch for stalemate tricks when you’re winning is a very important chess lesson. Look up Eric Rosen stalemate traps on YouTube. This is an IM who regularly tricks GMs into stalemate. The GMs are not mad at him, only themselves for falling for it.
Bootvis 5y ago
Swindling is part of the game at all levels. Personally, I feel good about it even at 35 as long as I followed the rules. I remember a kid changing the colour of his bishop by 'misplacing' it on a different colour square to get the same colour in a bishop-pawn endgame. That was not OK.

selcuka 5y ago

There's also The Kilobyte's Gambit [1], which is a chess engine written in 1024 bytes of JavaScript. [1] https://vole.wtf/kilobytes-gambit/ https://vole.wtf/kilobytes-gambit/

xwdv 5y ago

Why bother implementing rules at all? Just create an interface to move pieces around on a board wherever you want. If you play chess you should know the rules and how to move pieces.

greyman 5y ago
I kind of agree, chess without promotions, castling and en passant is not chess. But the guy also made full version, with impressively small size: For real purists: a close-to-minimal version that does understand full FIDE rules including under-promotion can be found here. It measures 1433 characters. (although I don't know why people who adhere to chess rules are called "purists", but whatever. :-))
- xwdv 5y ago
  In Ultima Online we would play chess to pass time on long sea voyages while hunting for monsters or treasure. There was no rules engine, it was just a simple board where you could drag and drop pieces around on any which way, which allowed for a lot of flexibility in how you played. We could even play random chess this way.

thom 5y ago

Don't know if the author frequents these parts, but I really enjoyed the annotated Toledo chess source book, and would very happily pay for similar here!