Courage is Better With Cowardice


My ants had already learned courage, and now they know the importance of cowardice. It’s been about two weeks since I uploaded a new bot, and this new version is much improved. The last real version of my bot was able to play 63 games, and ended with a skill rating of about 58.

Today’s intelligence level: real swarm.

It took a couple of deploys to get the newest version of my bot up, but after only a few games it’s now rated at almost 69. At the moment I’m typing this, my bot is once again the best Clojure bot in the content, and is on the edge of the top 500 (although I expect to fall out shortly).

After doing some simple work on my bot (such as using the random seed the content provides to let you run game replays correctly), I found and fixed the bugs I had mentioned last time. The biggest problem the last version of my bot was having (besides stupid behavior due to bugs) was defense. Since the ants didn’t care too much about enemy ants (and sometimes actively avoid them) under the right circumstances it was possible to walk in and take one of my hills without too much effort. The bug fixes made this worse as the ants spread out better so there were fewer to act as defense.

This was fixed by implementing a strategy that I thought of a while ago, but was remedied of when I saw a competitor using it. By strategically placing ants around my hills I can raise the bar for anyone trying to attack. In the picture at the top of this post you can see my 2nd level arrangement (out of three). This simple defense works great against single file streams of ants. Combined with new code that causes all nearby ants to run home if the hill gets attacked my hills have been able to survive much longer than they ever would have before. In some games, an enemy loses all their extra resources unsuccessfully trying to take my hill.

Things aren’t perfect. A side effect of the way things work is getting an ant near one of my hills can, under circumstances that aren’t nearly rare enough, prevent my bot from doing any further work. My colony may survive, but it’s not out gathering food or razing other hills. This in combination with a large number of opponent ants means that my bot can be shut down and eliminated by a correct show of force.

The last thing I had to do was fix a problem I didn’t expect to have: my bot times out. In easy games (especially the initial “does the bot crash” game bots run through when first uploaded) my bot can generate so many ants that it actually goes over it’s turn time. I added a little code so skip processing ants when my bot is about to run out of time, and I have seen it in action in production. Due to some quirk of the Python server implementation the order of ants to the bots being tested in is a discernible pattern. So when ants stop moving (because I ran out of time and didn’t get to issue them any orders) it makes a very obvious pattern on the field.

While the code seems to work very well, it does still fail on the ultra-small test map for some reason. I’m going to have to keep an eye on my bot to see if it happens in any other games. I may have to make it more aggressive.