Starcraft AI blog

Martin Rooijackers sent me some information about his creation LetaBot.

Up through AIIDE 2015 LetaBot selected builds by learning, but now it has jettisoned learning and selects builds based on scouting information. LetaBot opens with a build that is safe against rushes and transitions to counter whatever it scouts—at least up to a point, it’s a work in progress. LetaBot now has “an extensive flowchart” (that’s how he put it) of terran build orders from Liquipedia. That makes it sound like LetaBot will make more than one transition if it thinks it should.

Rooijackers credits Dennis Soemers (author of protoss bot MaasCraft, which played in AIIDE 2014 and CIG 2014) with pulling the build orders out of Liquipedia, and says he got more build order tips from mapmaker CardinalAllin.

You can see why he might have wanted to change—LetaBot didn’t really benefit from learning in AIIDE 2015. An advantage of prior knowledge over learning is that knowledge is available from the start; you don’t lose games figuring stuff out. A disadvantage is that you can’t take special advantage of surprise weaknesses in the opponent’s play. And I notice how much AIUR wins with strategies that are objectively bad.

Ideally bots should both have prior knowledge and learn during a competition, of course. Prior knowledge says “here are the builds or strategies that work” and learning adds “and these are the particular ones that you should pick to gain advantage over this opponent/this opponent on this map/etc.”

I think that offline learning would be a good way to gain knowledge of builds and strategies, especially if you have vast resources like most of us. You don’t want to go with builds that are good, you want to go with builds that are good for you, based on your skills; that’s true for any player. So every time you make a tweak to micro that may affect your choices, be sure to spend a few cpu-years on offline learning to re-learn your openings from scratch. Should be no problem if you’re as rich as Google, and who isn’t?