Just a mention of the Rodent IV chess engine

EDIT - See Posts #12 & 16 for a minor bug I stumbled upon.

I just wanted to mention the existence of the Rodent IV chess engine. If you enjoy playing with engines that have personalities and can be dumbed down, you might want to check this out.

The programmer states that this will be the last version of Rodent. There are not a huge number of available personalities, but you can create your own personalities if you so desire. The personality implementation is new in this version, so personalities from older Rodent versions don't work in Rodent IV.

As I see it, the big advantage of Rodent IV is that setting the Elo level is now completely decoupled from the selected personality.

The download page is:  http://www.pkoziol.cal24.pl/rodent/rodent.htm

The direct download URL is:  http://www.pkoziol.cal24.pl/rodent/FinalRodent.7z

Cool! Thank you very much.

Are we given directions as to what to do with the downloaded file FinalRodent.7z?  My computer does not recognize it as a zip file to unpack nor any form of executable.  The file extension .7z  is meaningless to my OS.  EDIT  OK.  I am not up to speed with current computer stuff.  7z is a current zip type file to be unpacked with ... whatever.   Sorry! 

So how are we supposed to use these personalities if it's just an engine we get to download!?

You'll have to install the engine into a Graphical User Interface (GUI) that is compatible with UCI engines. Most GUIs will work (such as Arena, Lucas Chess, Scid, Scid vs PC, etc.).

https://www.howtogeek.com/357846/what-is-a-7z-file-and-how-do-i-open-one/

For Windows, 7-Zip is my favorite utility for opening 7z files.

I knew that already, but there isn't an option to choose any personalities in the GUI itself. That's what's bothering me.

@chess_juice thanks for help. It worked for me.

Congratulations. This isn't about you however, it's about the rodent chess engine.

You're still talking about yourself. If you want people to discuss you, make your own thread. No need to hijack others.

To the OP - I'll try it with my Certabo board this weekend. Thanks for the tip.

Well, I guess I didn't test the engine enough before making the thread. I ran the default engine configuration in Arena without a personality at low Elo levels, and everything seemed fine. It played at the expected low Elo level (1000 elo), and I created the thread.

Later, I tried running one of the personalities at a low Elo level, but 90% of the time, it would only run at full strength. I've tried changing settings to determine the cause of the problem, but so far I'm at a loss for the reason.

So, Rodent IV appears to have problems running personalities at less than full strength, at least in Arena. (I haven't tried it in other GUIs.)

Sorry for the false start. If I figure all this out, I'll post the solution.

I managed to play "Grumpy" at ELO 1200 using Arena 3.5 (not 3,5,1).  Don't know if it actually played at a 1200 level, but the moves in the engine window never went much above 4 or 5 ply.

I tried using the the Certabo GUI and my board. I didn't get it to work yet.

If it was only going 4 or 5 plies deep, I'm sure it was playing at the right Elo level. At full strength, it would be hitting at least 15 or 20 plies, as long as you weren't playing super fast games.

I think I have a handle on the problem. As stated before, if you're playing the engine at low Elo levels WITHOUT a personality file, everything is fine.

However, if you're playing the engine at less than full strength WITH a personality file, everything is still fine - until you restart the engine or the GUI - then the lower Elo setting is lost, and the engine will run at full strength. In other words, when coupled with a personality file, the Elo setting is not persistent - Whenever the engine is restarted, the Elo level must be reset if you want to play at less than full strength.

This isn't a problem if you're just playing a few games against a weakened personality, but if the engine is playing in an engine-engine tournament consisting of many games, you have to be aware of this lack of persistence problem. (Arena recommends restarting the GUI after every 20 games of an engine tournament.)

The reason that I stumbled upon this persistence problem so quickly is that I have a habit of configuring an engine, then immediately restarting the engine to ensure that the reconfigured settings are resident. This habit works great, as long as the settings are persistent. However, in this case, I was just configuring the weakened Elo setting, restarting the engine, and immediately losing the weakened Elo setting. :-(

Engine author here I'm glad You are interested in Rodent IV. Right now I can't work on the engine with the intensity of the last 10 years or so, partly because since 2 years I develop game engines at work, and doing the same in my spare time is not my idea of a hobby. However, I am making a last-ditch effort to transform Rodent into a community project, see https://github.com/nescitus/rodent-iv

Those of You who have some experience in chess programming can join and try to fix stuff that You consider broken.

As for Elo persistence, I'm not entirely sure whether problem is caused by engine or by GUI. UCI protocol allows to set a personality by an option, and Elo by a separate UCI_Elo command. If personality is persistent, and Elo setting is not, it seems that they are handled differently by the GUI

If everything else fails, it might be possible to create a Rodent_Elo option, which should be persistent, but it would be against the spirit of protocol, so I am extremely wary to do that.

Hi Pawel,

First of all, thank you for all the work you've done on the Rodent versions!

Secondly, I fully understand the need to separate work from hobby. I doubt that it's healthy to work on the same thing 24/7.

Thirdly, in the back of my mind, I knew that I should have tried the "bug" on one or two other GUIs, but I was lazy. Oopsie! (I may try that when I can find some time.)

And finally, I have to admit that I'm not a programmer, and the only thing I know about GitHub is how to download files from there - The rest of GitHub is Greek to me. I can only hope that another programmer will resolve the persistence issue, that is, if the GUI isn't the problem. And if the problem IS the GUI, then it's only a matter of finding the right GUI.

And, even if nothing gets resolved and I don't find a better GUI, I can still live with the situation - It will just require a bit of hand-holding during use.

Thanks again for creating the Rodent series - It's a really fun engine.

FYI, I couldn't get the Elo persistency to work in either Winboard 4.8 or Lucas Chess.

And engine-community-author number 1 here

Also short words about me:
before a few weeks I've little bit "gambled" with the source code of rodent (for example also added chess960).
Than I asked Pawel, how to publish my version. I don't like to publish my bugs and call it "rodent", so all world will think how bad Pawel are working and I also don't like to create an own name, so all world will praise me (not recognizing my very little contribution).
For my surprise, Pawel made me co-author, which made me proud, but in result impose a lot of work and responsibility to me.

All over, the days of quick'n'dirty work.

It make me happy to read about rodent, but a little bit unhappy, that (as usual in internet) on different places.
For example read also this thread:
http://talkchess.com/forum3/viewtopic.php?f=2&t=73132

Oh yes, and I'm focusing to android platform!
But rodent has a lot of platform independent things:

The TO wrote, there are not too much personalities available. I would like to make a big collection.
Also that one from rodent3 are still working. Only a few options are new and have to be set (if not doing, default values are used) and some other (piece values) are split to middle- and end-game (addition Mg/Eg). I thought about automatically load this value, but better do it manually and create real rodent4-personalities from them.
Still I'm thinking about how to handle sets of personalities (speaking later about it).

And I guess, exactly this thing with rodent3 is the problem, told in this thread.
To make it possible to load r3-personalities, the values were reseted each time - also the values for reducing strength.
I've checked the code and hopefully fixed this thing.