Starcraft AI blog

More delays for the burrow post. I have a busy weekend.

For some reason, I’ve been working on openings a lot for this version. Looking at Microwave’s openings, I noticed “5Pool Zergling Hell”, which researches speed for the zerglings after the second hatchery. That is very late zergling speed, and it didn’t seem to fit with the rush build. That may be why Microwave doesn’t use it; by the time speed finishes, the game is probably already won or lost. But it gave me an idea.

This morning I coded up a 6 pool speed opening. By using the extra drone on an extractor, the build can produce 3 zerglings before hitting the supply limit, just like 5 pool, and ends up with the same drone count. 5 pool gets the zerglings a little faster and also can start the second hatchery sooner because it spends less, but zergling speed is powerful and (I reason) should make up the difference. 6 pool is a little slower, but it’s still a fast rush.

During testing, I noticed that Steamhammer’s 5 pool opening was optimized for 3- and 4-player maps, an unfortunate choice since it is played most often on 2 player maps. The difference is the income produced by the scouting drone, which is not needed on a 2-player map. So I also coded up 5PoolHard2Player as a separate build, and configured it to be chosen over 5PoolHard on 2-player maps. The rush becomes a little bit meaner.

6 pool usually beats 5 pool head to head; the extra drone is used up, so the advantage is zergling speed. 6 pool puts up a surprisingly tough fight against 9-9 gate before losing (as it should, since 9 pool loses too), and it tends to beat the 8 barracks bunker opening that Steamhammer terran relies on to defend fast rushes. The rush is slower but need not do as much damage to succeed, because the extractor and zergling speed make it easier to transition to the middle game. Overall, I conclude that 6 pool speed is about as dangerous as 5 pool, and it poses a different challenge to opponents so it is worth having.

All the rush openings should become stronger when I fix the bug in the building manager which causes unnecessary worker movement before starting a building. It’s on my list to fix soon.