Starcraft AI blog

I watched the SCHNAIL video and I’m pleased. Today I added a HumanOpponent flag to Steamhammer’s configuration file, to make the bot more fun for humans to play against. If you set it to true, the flag has 2 effects:

1. It tells the opponent model that the opponent is unpredictable, which the opponent model takes to mean “I’d better be unpredictable too so I can’t be exploited.” It chooses openings more randomly. This is just turning on a standard Steamhammer behavior that already existed.

2. When losing, Steamhammer ggs out much earlier. Steamhammer in the past assumed that its opponent is a bot and may mess up the win, so it surrenders barely one step before it is provably unable to win. (Even so, I’ve seen a couple games over the years when it might have won if it hadn’t given up—when it had no drones and no combat units and no money, but had units in production that could outfight the opponent which was also near death. It’s extremely rare.) Versus a human, that gg timing is way way too late, unacceptably late. When HumanOpponent is turned on, Steamhammer follows a two-part rule: A. The enemy is much stronger than me—my supply is less than half the enemy’s known supply. B. I have been hurt—my supply has fallen below half of its high water mark. The B part ensures that Steamhammer doesn’t give up without a fight merely because it has been grossly outmacroed.

I’m curious to find out how well the gg rule works in real human games. In test games, I thought the gg still came later than a strong human would prefer. But perhaps it is a good fit for human players who deem Steamhammer an interesting opponent. Also, the enemy’s known supply is generally less than the enemy’s true supply, and Steamhammer is weak at scouting so often it is much less. But I will need to improve scouting as part of my strategy adaptation project, and gg timing may improve when I do.

About SCHNAIL: Obviously we can’t expect SCHNAIL users to edit Steamhammer’s config file and set the HumanOpponent flag. The file won’t be exposed to them at all; they don’t need to know it exists. I asked Sonko if there will be a way for a bot to tell that it is running under SCHNAIL. Whatever the final arrangement ends up being, I will help Steamhammer fit into it so the bot does sensible things in human games.