Starcraft AI blog

Here’s a fun SCHNAIL game, Steamhammer-HitHat (screen name Joongwan). Steamhammer had played this opponent before, so it had an idea of what to expect and made an early sunken. The sunken is misplaced. The misplacement is better against other bots than correct placement, but you’ll see in the game why I call it a misplacement! After learning by the loser, the next game went differently. Another interesting game is this one on Fighting Spirit against a different opponent.

I’m not sure why there are separate screen names and game names. The website comes with an API that gives the screen name with replay, and the replay has the game name, so no information is hidden. Still, people use the feature a lot, so it must have appeal. Are names that much fun? I’m guessing it was a feature added at the request of players. I sure wouldn’t have thought of it.

Steamhammer 3.5.1 is progressing, though slowly. Since my energy ran down, I stopped working on my plan of using Steamhammer’s new opening data. After seeing many SCHNAIL games, I’m mostly making changes to improve Steamhammer’s play against humans. Humans know a lot of tricks that bots don’t know, and they’ve uncovered weaknesses that I want to fix. Better is better, even when it may not show against bot opponents.

I rewrote Steamhammer’s crufty old code for deciding when, and in what bases, to place sunkens and spores. Unlike bots, humans are quite good at attacking vulnerable bases first. (Steamhammer makes an attempt to get this right. Most bots don’t try.) I was running the first tests, demonstrating that it worked in a couple of simple situations, when I realized that I should have generalized it for all races. Terran and protoss desperately need the skills: Make mutas and win because terran doesn’t add turrets; make DTs and win because only one base gets turrets or cannons for detection. I’m not only working slowly, I’m thinking slowly.... I rearchitected it and rewrote nearly all the code a second time, in a new StaticDefense class. It’s cleaner and more capable, and should be easier to adjust. It’s just now ready to get back to testing.

Humans make very different opening choices than bots. Most stick with general-purpose safe openings; a few specialize in cheese. I don’t have any way to collect SCHNAIL opening data, so I started a new file to hand-write an anti-human configuration. I didn’t fill in much of it yet, but I’ll get to it.

I expect my tweaks and new features to help somewhat on SCHNAIL and a tiny bit on BASIL. But we’ll see.