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Arimaa >> General Discussion >> Bait-and-tackle
(Message started by: IdahoEv on Nov 8th, 2006, 3:08pm)

Title: Bait-and-tackle
Post by IdahoEv on Nov 8th, 2006, 3:08pm
Does anyone have a code system that can determine how many times people have used bait-and-tackle against bots in the database?

Title: Re: Bait-and-tackle
Post by Fritzlein on Nov 8th, 2006, 11:15pm
I don't know how often bait-and-tackle has been used, but this gives me an excuse to tell a potentially interesting story about Bomb.

In March 2005, after the 2005 Arimaa Challenge had been successfully defended by Belbo, Fotland spent a little time developing Bomb.  As far as I know, that was his last stint of active development.  In one of my games against BombBlitz (then known as bot_lightning), I was startled that Bomb passed up an opportunity to blockade my elephant behind its trap at essentially no cost.  I asked Fotland about it, and after some research he told me there was a bug in the blockade code that made Bomb think my elephant could walk to freedom through the trap.  See the comments to game 12417.

He immediately fixed the bug, of course, and I considered that the end of the matter.  I didn't recall this until after the 2006 Challenge match, when we all discovered that Bomb2006 was actually Bomb2005.  Apparently Fotland lost some version of Bomb due to a crash, and didn't have time to get a stable, improved version running again, so he just went with the year-before code.  In particular, the walk-though-the-trap bug in the blockade evaluation was still in Bomb2005 and thus is still in the best version of Bomb we are able to play against today.

What this means to me is that (very probably) bait-and-tackle only works due to an evaluation bug that Fotland has already fixed.  We can take advantage of blockading Bomb in this way, not because it is a hard problem to solve, but because the fix hasn't made it into a publicly playable version of Bomb.

I spent some time tonight reading my comments to my games against bot_speedy (a.k.a. BombFast) in late 2004.  I said some amusing things about Arimaa strategy, for example that getting a camel hostage is worth sacrificing two cats, and that getting HDR for M would be a bad trade against a human.  Nowadays we know that neither camel hostages nor camels are worth as much as I thought back then.

But what struck me even more was that, during the times that Fotland was actively developing Bomb, it was no easy task to stay ahead.  There was a real sense of uncertainty about whether humans would be able to keep an advantage, or whether everything humans discovered about strategy could just be put back into the bots by the developers.  I certainly thought then that Fotland's continuing tweaks to Bomb were adding points to its playing strength at a palpable rate.

I think I have a tendency to extrapolate the recent past into the future, which in this case means I tend to think that the gap between humans and bots will tend to get wider every year, and that the Arimaa Challenge prize is safe well into the future.  Reading those historical notes reminds me not to get too caught up in the present.  The day may not be so far off that the competition tightens up again...

Title: Re: Bait-and-tackle
Post by IdahoEv on Nov 9th, 2006, 4:32am
Wow.   That is truly fascinating.


on 11/08/06 at 23:15:58, Fritzlein wrote:
What this means to me is that (very probably) bait-and-tackle only works due to an evaluation bug that Fotland has already fixed.  We can take advantage of blockading Bomb in this way, not because it is a hard problem to solve, but because the fix hasn't made it into a publicly playable version of Bomb.


That blows my mind.

Title: Re: Bait-and-tackle
Post by PMertens on Nov 9th, 2006, 1:54pm

Quote:
.. but this gives me an excuse to tell a potentially interesting story  ..


do you really need an excuse ?  ;)

Title: Re: Bait-and-tackle
Post by IdahoEv on Nov 9th, 2006, 3:25pm
So do we know anything about Bomb2007?  



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