Starcraft AI blog

Today, a post about things I wanted to do and didn’t get to, or started to do and rolled back or didn’t finish. I accomplished a lot, but the to-do list is functionally infinite.

• UAlbertaBot executes unit orders as they are issued during the frame, retaining no state beyond what BWAPI remembers. Steamhammer inherited the system. I am in the process of changing it to record the orders and save status info, then issue any needed orders at the end of the frame. Adding the Micro object in the last version was one step. The Micro object now records the order and status of each of our units, and has all the infrastructure it needs to issue orders, including its own update() method with TimerManager calls to track how long it takes. But it doesn’t actually issue orders; there is no effective change to the micro system.

When this is done, it will be easier or possible to unstick units, to make sure units don’t get stuck in the first place, and in general to control units precisely.

• I worked a bit on analyzing Steamhammer’s use of the combat simulator. Improvements are there for the taking, but my first try was not successful and I left it for later.

• McRave suggested that micro to avoid big damage attacks was key. Equally important is to pull off big damage attacks yourself. Besides plague, the zerg big damage attack is scourge suicide, and Steamhammer sucks with scourge. Scourge control is on my list, but never came to the top.

• I implemented mine dodging to reduce the danger of spider mines, but the way I did it was not useful for zerg. Reacting to mines is tricky: If a mine pops up, sometimes you should drag it to the enemy, sometimes drag it away from your other units, sometimes shoot it down. I lost the “just shoot it” case, and it was a net disadvantage. The feature is in the code but is disabled.

• Steamhammer’s lurker skills were adequate for when they were implemented, but have fallen behind the times. It needs to stop doing things like burrowing one lurker at a time in cannon range.

• I haven’t done anything to improve overlord safety, dark templar reactions, or any of that stuff. Many weaknesses there.

• I planned and promised a skill to put pressure on the enemy in the early or middle game, but did not finish one. I had several ideas, and all of them hinged on what I call raiding: Harassing where possible, moving around but staying near the enemy, not retreating to rejoin the main army. Harassing mutalisks can be considered raiders in that sense, and so can Krasi0’s vultures and Bereaver’s reaver drops. Runby units and dropped units should act as raiders, and Steamhammer doesn’t have the skill—with a Hold order, they go idle if they clear their area to hold, and with an Attack order they may try to retreat to the main base. Picking up dropped units is also a good raiding skill.

• I implemented a Watch squad, but did not polish it up enough that it became useful. It is turned off. It had several purposes. It could keep watch on expansions and chokes, sometimes making it possible to disband the Recon squad. It could prevent enemy expansions in some cases, and clear mines and verify the safety of expansions that we wanted to take.

• I thought of adding pre-learned opponent model data for the fixed opponents carried over from last year, plus opponent model hint configuration (like “try this first and see how it works”) for opponents that I think I know something about. PurpleWave, we’re told, did an elaborate job of that for CIG this year. The idea of hints is that the opponent model can save exploration time if the hints are right, winning more games, and correct itself with little loss if the hints are wrong. I decided that, since AIIDE is a long tournament with plenty of time for learning to converge, other work would probably help more.

upcoming

Done with the testing, today I am resting. I’ll upload zerg-only Steamhammer 2.0 to SSCAIT tomorrow. On the blog side, I think I’ll start with an overall evaluation post, what I’ve done and how successful it seems, and follow up with posts about specifics like defiler skills and squad restructuring, and then the big detailed change list. At some point soon Steamhammer 2.1 will slip in. 2.1 will likely have a few minor fixes and deserve its own little change list.

Shortly, CIG should release its detailed results. They promised source and replays. If they also provide a game result log, I’ll analyze it and post my usual colorful summary tables. Not sure how that will fit in with the other posts, the blog may have a busy time.