Near-random movers

Discussion of chess software programming and technical issues.

Moderators: hgm, Rebel, chrisw

Robert Pope
Posts: 558
Joined: Sat Mar 25, 2006 8:27 pm

Near-random movers

Post by Robert Pope »

I think I recall somebody making a series of random-move engines to create a progression of engines on the very low end. e.g. pure random mover, random mover unless mate-in-1 exists, etc. They were built off a solid engine, so they didn't have instability from crashes.

Ring any bells? Does anyone know where I can download them?
Modern Times
Posts: 3546
Joined: Thu Jun 07, 2012 11:02 pm

Re: Near-random movers

Post by Modern Times »

There us a Brutus random mover on CCRL 404. Follow the download link on that page.

http://www.computerchess.org.uk/ccrl/40 ... Brutus_RND
User avatar
Werner Taelemans
Posts: 119
Joined: Mon Feb 03, 2014 11:57 am
Location: Belgium
Full name: Werner Taelemans

Re: Near-random movers

Post by Werner Taelemans »

Robert Pope wrote:Ring any bells? Does anyone know where I can download them?
Take a look at this thread:
http://talkchess.com/forum/viewtopic.ph ... 07&t=62510
Robert Pope
Posts: 558
Joined: Sat Mar 25, 2006 8:27 pm

Re: Near-random movers

Post by Robert Pope »

Werner Taelemans wrote:
Robert Pope wrote:Ring any bells? Does anyone know where I can download them?
Take a look at this thread:
http://talkchess.com/forum/viewtopic.ph ... 07&t=62510
That's the thread I was thinking about - thanks!
AlvaroBegue
Posts: 931
Joined: Tue Mar 09, 2010 3:46 pm
Location: New York
Full name: Álvaro Begué (RuyDos)

Re: Near-random movers

Post by AlvaroBegue »

I made a version of RuyDos that plays randomly, at the request of someone in these forums.

https://www.dropbox.com/sh/1o3ymy403yy8 ... 0-MUa?dl=0

Enjoy!
Álvaro.
flok

Re: Near-random movers

Post by flok »

Not really random (really not), but with the rating of one: https://vanheusden.com/pos/
Volker Annuss
Posts: 180
Joined: Mon Sep 03, 2007 9:15 am

Re: Near-random movers

Post by Volker Annuss »

Arminius http://www.nnuss.de/Hermann/Arminius2017-01-01.zip has a random mover built in. When you give him the command line argument --Rnd he is a random mover.

When you give him the command line argument --RndMate he will find every mate in one. When there is no mate in one, he is a random mover.
User avatar
Luis Babboni
Posts: 464
Joined: Sat Feb 28, 2015 4:37 pm
Location: Argentina

Re: Near-random movers

Post by Luis Babboni »

Soberango still has a non sofisticated evaluation function, in fact just based on material, and when more than one move have the same evaluation and the same priority in move order, chose wich to do it nearly* random.
*: said "nearly random" cause for example in case of bishop, tower or queen, the less distances moves are choosed over biger distances moves. But for example knight moves that not allowed or avoided mate in its horizon distance view and with no capture or capturing the same kind of piece, are choosed by pure random.
This way, and without lost time (or very few at most) cause the way it uses to be random in those cases, near never do the same game.
Robert Pope
Posts: 558
Joined: Sat Mar 25, 2006 8:27 pm

Re: Near-random movers

Post by Robert Pope »

Thanks, I validated my RandMover and RandMater against Arminius. I also made a normal searcher that returned a random number instead of the regular eval. That version scored 600 elo better than a RandomMater. Is that to be expected?
Volker Annuss
Posts: 180
Joined: Mon Sep 03, 2007 9:15 am

Re: Near-random movers

Post by Volker Annuss »

Robert Pope wrote:I also made a normal searcher that returned a random number instead of the regular eval. That version scored 600 elo better than a RandomMater. Is that to be expected?
Does your version find deep mates? It is known, that a random eval helps the search to find positions with high mobility.