UCI chess engines with low ELO (<1700)

[rdhoffmann]

I'm trying to write a weak chess engine (for human play, to have fun with). In order to know roughly the ELO strength, it could be useful to play against other engines.

Does anyone know chess engines rated below 1700 or so, which are:

- stable under UCI protocol
- free
- not always making the same move, esp in the opening

I recall the engines that come with Arena are well above 2000 already and thus far too strong for this purpose.

[Carbec]

Hi,
There are some ; look at ccrl.chess, complete list.

[towforce]

One option is to play against chess.com's "bots".

[jefk]

look at the Lucaschess package,
https://lucaschess.pythonanywhere.com/

there are quite a lot with rating < 1700. Even lower than that (they not always play
in human style, eg. taking sufficient time per move, but that's another matter

And then there are quite some engines with the UCI setElo-strength option,
(or skill level correlated with Elo as described eg in a readm.txt or .ini)
not sure which ones would play in a realistic manner below 1700,
years ago i liked the Ufim engine to (occasionally) spar against, and
nowadays there are ofcourse the maia bots 1300 and 1500 , also included
in the later versions of lucaschess

[rdhoffmann]

Hi,
There are some ; look at ccrl.chess, complete list.

When I was looking for low-rated engines years ago using that list, I could hardly find anything working though. Many links are dead, sometimes there is no Windows binaries, the UCI protocol is not implemented (or not properly) or there is other bugs/issues.

I'm looking for something stable like AnMon or SOS 5.1 just with 600-800 ELO less. Maybe someone knows such a robust low-rated engine

look at the Lucaschess package,
https://lucaschess.pythonanywhere.com/

there are quite a lot with rating < 1700. Even lower than that (they not always play
in human style, eg. taking sufficient time per move, but that's another matter

Thanks will check!

[JohnWoe]

Robust low rated chess engine is oxymoron. They are low rated because they are full of bugs. When you fix the bugs the low rated chess engines become high rated chess engines. When I developed my engine. I thought I could take some low rated engine from ahead from list. But none them even compiled/worked without Herculean effort.

[chesskobra]

Maybe instead of using bad and buggy engines, use robust engines that have skill levels - Crafty, Phalanx, Arasan, Stockfish, Komodo, various Leela networks (e.g., Maia networks) or low nodes configurations of Leela.

[rdhoffmann]

Robust low rated chess engine is oxymoron. They are low rated because they are full of bugs. When you fix the bugs the low rated chess engines become high rated chess engines. When I developed my engine. I thought I could take some low rated engine from ahead from list. But none them even compiled/worked without Herculean effort.

True, my best chess engine was just like that while <2200, barely working and with a poor UCI implementation. I just thought maybe someone coded a nice "educational" engine that does not really care about playing strength much.

Maybe instead of using bad and buggy engines, use robust engines that have skill levels - Crafty, Phalanx, Arasan, Stockfish, Komodo, various Leela networks (e.g., Maia networks) or low nodes configurations of Leela.

Do we know their approximate ELO rating, when set to a particular skill level?

[chesskobra]

Crafty (version 25.6, which you will have to compile) has Elo levels as opposed to numbered skill levels, set on command line as 'elo=2100'. I think I have read somewhere in the documentation that below 1500 they may not work well. I don't know how well the Elo levels correspond to CCRL. But from my (small scale) experiments, Crafty Elo levels above 2000 seem to correspond well with engines rated on CCRL and with each other. With other engines you will have to experiment to determine their approximate levels, but for testing an engine it should not matter too much.

Crafty and Phalanx are xboard engines, though. But that is not a problem to run tournaments under cutechess.

[rdhoffmann]

Thank you, I can see I can adjust this in CuteChess. Never experimented with such options before (always ran engines at their default/best mode).

So this is way better than having to deal with buggy low-rated engines, even if it may be somewhat less precise.