Starcraft AI blog

Martin Rooijackers aka LetaBot read my posts about Zia and wrote to point out that a zerg bot facing terran wants both mutalisk and lurker options. The reason is that terran may counter the mutas. He mentioned 5 barracks with +1, which should hard counter mutas. He also called out valkyrie and goliath possibilities, specifically pointing out that valkyries force mutas to spread out, which reduces their potential. Zerg needs to scout the build and react before overcommitting to mutalisks—at the latest when the first fliers arrive at the terran base and see what’s up.

Zerg can’t stick with tier 1 units (zerglings and hydralisks) because any likely terran midgame army will walk over them. And hive tech takes time. Lair units are key to the middlegame.

If zerg always goes mutas, any terran with strategy learning will find a way to counter the mutas and gain an advantage every game. I think this has already happened with Zia and Tscmoo terran. If zerg sometimes opens mutas and sometimes lurkers, then terran faces a risk trying to counter mutas with marines—the lurkers counter marines. Terran’s best play becomes less committal and more cautious, and that favors zerg.

Mainline pro play has the zerg starting with a limited number of mutas and using the time they buy with cautious harassment to get lurkers and rapidly tech to hive. But pros of course are totally comfortable with adaptation and tech switches. Not all games follow the main line. Today’s game of Flash (T) vs. Zero (Z) was a great example: Flash opened 14 CC, Zero responded logically with 3 hatcheries before pool and went lurkers while Flash prepared for mutalisks.

Any bot with only one strategy stands at a disadvantage against bots with opponent modeling. It’s true for all matchups. Today’s simple strategy learning will find a counter-strategy within a dozen games, usually less. Humans, and tomorrow’s sophisticated opponent modeling bots, may counter the strategy of the first game in the second, and should quickly find strong counters to most fixed strategies.

To beat humans, or to beat opponent modeling bots, you’ll need strategy flexibility plus either learning or a dose of randomness, ideally both. I promise. If sophisticated opponent modeling doesn’t arrive fast enough for me, I’ll provide it myself. It will make bots much more interesting to watch and to play against.