Starcraft AI blog

Two surprise upsets today caught my interest.

new from MadMix

The game MadMix by Oyvind Johannessen vs McRave surprised me.

McRave fell out of the top ranks a while back, but has lately been climbing back up. I’m guessing that some new subsystem was switched in a while back, and it has taken this long to work the bugs out. After a long drought and a bunch of tries, the new version of McRave notched its first recent win versus Steamhammer today (and another shortly after). I expect McRave will keep rising and return to the top 5 before long.

MadMix is brand new, but already has a big update. The initial version made most units for all races, but never researched upgrades or tech. Today’s version researches most upgrades and at least some tech, so the mix is even madder!

In MadMix versus McRave, random MadMix rolled zerg and started off with fast lurkers. McRave is much higher ranked and has a better build order, better tactics, and better micro. McRave had a vastly superior force in the early game, but for some reason chose not to engage—mistake #1. When the lurkers came out, McRave had no detection and was contained despite MadMix’s poor combat skills.

MadMix slowly expanded to many bases while McRave was contained. McRave made a robo facility but never added an observatory, so it had no detection—mistake #2. I’m sure it’s an oversight or bug and will be fixed before long. McRave still could have made a nexus at its natural, added cannons for detection, and maintained a chance to win, but instead when the protoss main mined out, McRave resorted to long distance mining—mistake #3. Even so, McRave’s macro was stronger and the protoss army remained dominant. In smaller attacks, MadMix retreated support units and unburrowed lurkers each time targets moved out of range, so the forward lurkers tended not to live long. For a lurker, staying underground and restricting your enemy’s mobility can be more important than having a target.

McRave was strangely passive this game, moving its army mostly in response to immediate threats. With zerg on many bases and protoss long distance mining, the writing was on the wall. Eventually MadMix started mass attacks and broke through to win. The picture is from shortly after MadMix’s army first became the larger one (notice the worker counts). In the upper left you can see lurkers holding an isolated protoss force at bay; for some reason, MadMix made better use of its lurkers during the breakthrough attack.

The upgrades tab shows that MadMix did a ton of upgrades this game, even overlord sight range. You can see scourge, and offscreen is a devourer, even though McRave never made an air unit. The zerg unit mix is genuinely mad. It did not make queens, which may mean that it realizes it needs to know how to use the spells first.

Maybe another update soon will see MadMix using most tech, too. In any case, MadMix is already ranked higher than Travis Shelton, the other random bot with a wide choice of units.

Randomhammer gets a win over Krasi0

Randomhammer scored an upset win over Krasi0 with a vulture drop. I knew the drops would pull some good wins.

Randomhammer (this time) sent its dropship the short way around the edge of the map to Krasi0’s base. Randomhammer’s vulture micro was disappointingly poor, but even so the drop was moderately successful; it killed few SCVs, but stopped mining for a surprisingly long time as Krasi0 cautiously backed away.You can see in the production tab that Randomhammer is expanding and adding units while Krasi0 is producing nothing.

Krasi0 may have seen the building starport just before its scout was chased away by marines. In any case, it made goliaths with a few tanks mixed in, a good counter to the air units and vultures which were the only units it had seen indications of. But Randomhammer immediately switched to tanks (it’s a hardcoded tech switch—Steamhammer’s terran and protoss strategy is ultra-simple), and expanded not once, but twice.

Krasi0 delayed its expansion and did not have enough gas to make many tanks alongside the other tech it wanted. With 3 geysers, Randomhammer had greater tank numbers and was able to push through and win despite Krasi0’s superior tactics and unit control. Knowing how to position tanks on high ground is great, but if you have 2 tanks versus 6, it’s not great enough.