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        Arimaa >> Bot Development >> It's good to see bots being improved
        
(Message started by: Swynndla on Oct 16^th, 2011, 12:17am)

Title: It's good to see bots being improved
Post by Swynndla on Oct 16^th, 2011, 12:17am

I'm looking forward to see the line-up of bots for the next bot champs. From what it seems to me:

lightvector has made sharp parallel, fixed some bugs, and he's hinted at several other speed improvements that could be done.

tize been busy testing marwin with various ideas.

rbarreira is doing a complete rewrite of briareus's eval function.

ingwa is actively improving badger.

What are others doing? I'd be interested to hear (and also hear from the four above) ... It's exciting as sharp has set the stage for other developers to try new things.

Also, is there a page giving a brief description of each bot?

Title: Re: It's good to see bots being improved
Post by lightvector on Oct 17^th, 2011, 11:06pm

Whew, I only just got around to starting to work on sharp again. Since I began working two months ago and gotten involved in a few things, I've had essentially no time for anything Arimaa-related, whether it be coding, following the mob/gang game, etc. I'm starting to have time again, and hopefully it will stay that way.

During the summer, I did parallelize sharp, but the bot generally remains primitive in many ways. For instance, I only just now got around to testing a 'killer move' heuristic for the first time, which is one of way too many things that I should have tested a long time ago. The number of such things that I'll be able to try will depend heavily on how much time I can find. Judging by the last 2 months, it won't nearly be as much as I'd like...

So, that's the short summary over here. It looks like 2012's going to be fun!

Title: Re: It's good to see bots being improved
Post by Swynndla on Oct 18^th, 2011, 1:07am

Thanks for the update lightvector. It's exciting to know that sharp is being improved! So are you saying that sharp didn't use killer moves at all, or just that you hadn't tested one of the heuristics?

Title: Re: It's good to see bots being improved
Post by lightvector on Oct 18^th, 2011, 10:49pm

Sharp did not use killer moves at all.

I'm trying it right now. So far, looks like it's averaging close to a 30% speedup on a set of test positions. Much of this on the tail end, with the greatest speedups occurring disproportionately frequently among the positions that are the slowest and hardest to search deeply. But the median search improved too (10%). All in all, an excellent gain for such a simple change.

There's still some more low-hanging fruits left after this, each of which is likely (but not guaranteed, of course) to result in small gains.

Title: Re: It's good to see bots being improved
Post by Fritzlein on Oct 18^th, 2011, 10:59pm

Thanks for the updates, lightvector. Swynndla isn't the only one who is curious how the reigning champion bot is being improved.

Title: Re: It's good to see bots being improved
Post by rbarreira on Oct 19^th, 2011, 3:33am

Yes, I am doing a (much needed) complete rewrite of briareus's eval, and also adding missing capture/goal patterns some of which caused problems in the 2011 CC.

I also did a bunch of minor improvements such as disallowing reversible moves.

Perhaps more interestingly I made a quick & dirty hack to allow briareus to run simultaneously on several PCs cooperating on a search (basically a cluster version of the bot). It worked rather well on an actual cluster, but when I tried it on Amazon EC2 I found that their communication latency between machines sucks, which killed performance (even with the "cluster compute" instance which is supposed to have high-performance IO... it's possible I did something wrong with the setup).

Title: Re: It's good to see bots being improved
Post by Fritzlein on Oct 19^th, 2011, 8:02am

Thanks, rbarriera. Also I have enjoyed your chatroom discussions with ingwa and Migi. Although I am seldom in the chatroom, I always read the archives with interest before the week is out.

Title: Re: It's good to see bots being improved
Post by tize on Oct 24^th, 2011, 4:46pm

This year has been mostly focused on the search, by adding some kind of late move reduction, adding new static pruners and some search extensions.

As far as strategy goes there has been some tunings and small things like making the rabbits more aggresive in the end of the games.

Of course theres also the normal chunk of bug fixes.

With the bots being improved (or at least changed, I don't know if Marwin has got any stronger by the changes) it looks like we are up for an interesting tournament, and it's still almost 4 months of changes left...

It's good to hear that Sharp now will use all the processing power available. That tells us that the next champion will be stronger than the previous, hopefully Sharp will not be to lonely at it's new playing strength.

Title: Re: It's good to see bots being improved
Post by Fritzlein on Nov 11^th, 2011, 7:31pm

on 10/24/11 at 16:46:00, tize wrote:

It's good to hear that Sharp now will use all the processing power available. That tells us that the next champion will be stronger than the previous, hopefully Sharp will not be to lonely at it's new playing strength.

I hope at least that sharp at its new level has some human company! :) Thanks for the progress update on marwin.

Title: Re: It's good to see bots being improved
Post by Swynndla on Nov 29^th, 2011, 7:28pm

I'm a bit late in saying it, but when I saw Marwin play the other week, I was amazed at how strong it is now, and what advanced strategies it seems to be able to do now (like attacking with the camel - I'd guess not an easy thing to get right).

on 10/24/11 at 16:46:00, tize wrote:

... what ever you did seems to be working!

Title: Re: It's good to see bots being improved
Post by Fritzlein on Dec 10^th, 2011, 2:26pm

on 11/29/11 at 19:28:23, Swynndla wrote:

From playing marwin, and from losing two of seven, I second the perception of increased strength. If you want marwin to sharpen its claws against me some more, just make it available over the coming weeks when I am on vacation from school. :)

Title: Re: It's good to see bots being improved
Post by froody on Dec 10^th, 2011, 10:33pm

http://arimaa.com/arimaa/mwiki/index.php/Bot_List

Title: Re: It's good to see bots being improved
Post by tize on Dec 12^th, 2011, 2:58pm

on 12/10/11 at 14:26:13, Fritzlein wrote:

If you want marwin to sharpen its claws against me some more, just make it available over the coming weeks when I am on vacation from school. :)

I definitly want that. But it will have to wait a few days as I'm close to finish a small addition to the rabbit handling code that I want to get in before testing goes past the bots.

Title: Re: It's good to see bots being improved
Post by Fritzlein on Dec 12^th, 2011, 3:03pm

on 12/10/11 at 14:26:13, Fritzlein wrote:

From playing marwin, and from losing two of seven, I second the perception of increased strength.

A more persuasive hypothesis may be that I am getting worse. I just lost nine of twelve to Sharp2011Blitz. (No, this isn't my tactic to get out of defending the Arimaa Challenge this year; I just couldn't compete. :P)

Title: Re: It's good to see bots being improved
Post by leo on Dec 12^th, 2011, 4:11pm

@Fritzlein: But those were blitz games, and computers always win at shoot-them-ups (or rather would always win, if they weren't nerfed down ;))

(OK, I know my argument is only half-valid)

Title: Re: It's good to see bots being improved
Post by Swynndla on Dec 12^th, 2011, 5:35pm

No Fritz's games were Fast (ie 30 secs/move) not Blitz (ie 15 secs/move). This is significant as Fritz's track record against Sharp2011 is about even or so in Blitz, but he dominates in it in Fast (30 secs), but this new marwin seems to have jumped in strength even at 30 secs/move.

Title: Re: It's good to see bots being improved
Post by froody on Dec 12^th, 2011, 10:15pm

http://arimaa.com/arimaa/mwiki/index.php/Bot_List

Title: Re: It's good to see bots being improved
Post by Fritzlein on Dec 12^th, 2011, 10:46pm

It's true that my blitz record against bots is much worse than my fast record. That is to say, I suffer more from the speedup than an average human does.

There was a forum thread in which a two-parameter rating system was proposed: players would get a rating to reflect general playing strength and a "slope" to reflect how many rating points they gained (relatively speaking) for each doubling of thinking time. Of course it might not be linear, but the idea was to reflect in the simplest model possible that more time helps different people differently.

Indeed, iirc, 99of9 implemented this long ago when we had much less data, and found that Omar had an even steeper slope than I, whereas PMertens seemed to play just as well at blitz as at slow games. It would be interesting to re-run the model with the much larger dataset we now have.

[EDIT]
My memory was wrong. 99of9's numbers showed that I played just as well fast as slow, if not a little better. But I remembered correctly that Omar was horrible at fast games and PMertens very good at them. If anyone wants to investigate this with present-day data, this would be a good thread to bring back from the dead.

http://arimaa.com/arimaa/forum/cgi/YaBB.cgi?board=talk;action=display;num=1103741634;start=15

Title: Re: It's good to see bots being improved
Post by Fritzlein on Dec 12^th, 2011, 10:56pm

on 12/12/11 at 22:15:09, froody wrote:

http://arimaa.com/arimaa/mwiki/index.php/Bot_list

Thanks, froody. But why are there two of them?

Title: Re: It's good to see bots being improved
Post by froody on Dec 13^th, 2011, 7:52am

Me being stupid. Fixed now.

There are still details missing. Edit if you can, or post info here and someone will add it.

Title: Re: It's good to see bots being improved
Post by tize on Dec 13^th, 2011, 2:14pm

on 12/13/11 at 07:52:25, froody wrote:

Edit if you can, or post info here and someone will add it.

Ok here is some data: Marwin first appeared 2008 and is written in C++. The version that competed in 2011 was 1.4MB in size, and right now he is made up of ~27k lines of code (everything included).

Title: Re: It's good to see bots being improved
Post by rbarreira on Dec 15^th, 2011, 10:13am

on 12/12/11 at 15:03:30, Fritzlein wrote:

If it had been a tactic it would be rendered invalid by your latest winning streak of 8 games against Sharp2011Blitz and marwin ;)

Title: Re: It's good to see bots being improved
Post by Fritzlein on Dec 15^th, 2011, 10:52am

on 12/15/11 at 10:13:44, rbarreira wrote:

If it had been a tactic it would be rendered invalid by your latest winning streak of 8 games against Sharp2011Blitz and marwin ;)

Heh, I don't understand the difference. I didn't have some flash of insight to help me play better. Sometimes my brain works better than other times, for reasons unexplained.