Starcraft AI blog

The new protoss bot BananaBrain has been scoring about 50% in its first day online at SSCAIT. That’s quite good for a brand new bot. I also commend it for not having “bot” in its name.

The outstanding skill of BananaBrain is its macro. It has a seemingly excellent implementation of mineral locking, and likes to oversaturate its main and natural with probes so that when further bases are founded, they come online immediately. With that skill, BananaBrain often has a larger army than its opponent, and that can be the most important factor in winning. BananaBrain’s only macro flaw, as far as I can see, is that sometimes it wants to spend more gas than it has, with the result that it can’t spend all its minerals. It recovers after a while.

BananaBrain plays a fixed build against each race. The versus zerg build goes with mass zealots and and later adds corsairs, dark templar, and storm, but strangely never makes observers. That’s a wide range of units for a new bot (though MadMix is still the champion of making the most unit types when new). The versus terran and versus protoss openings are more generic, with a lot of dragoons. I haven’t seen a game versus random yet. Bots that learn will soon learn to exploit BananaBrain’s fixed openings.

BananaBrain’s skills other than macro are much weaker. Against zerg, the corsairs eagerly attack overlords without noticing whether they are under fire themselves. The game versus Tyr by Simon Prins shows that it is willing to ram a large army into prepared defenses and unwilling to retreat when losing. The strange battle with KaonBot shows that it is not aggressive enough to stop mass expansions and does not adapt to its opponent’s unit mix. BananaBrain also tends to neglect upgrades and research. Versus protoss it gets dragoon range only after zealot leg speed, even though it makes mostly dragoons (usually you should get dragoon range almost immediately). Versus terran it also makes many dragoons, and I didn’t see it get dragoon range at all.

Don’t be fooled by my complaints about its weaknesses. BananaBrain is doing well for a new bot. It even has a win over CherryPi.