Starcraft AI blog

Steamhammer 1.3 is uploaded. This is the release version. I’ll try to put up the source code and documentation today, so that I can hurry on to opponent modeling.

I’m convinced that Steamhammer 1.3 is stronger overall than the last release, 1.2.3. Some new bugs and weaknesses were added, as always, but more than enough old ones were taken away. Most of the new weaknesses fall into two groups: One, new macro problems revealed by fixing the last round of macro problems. Two, mistuning and general klutziness in the strategy boss because it has more tech choices. Adding lurkers, guardians, and devourers meant that I had to replace the subsystem that chooses the unit mix and tech target, and there are rough edges.

The change list since the last test version:

• Drop SparCraft and use FAP for combat simulation. SparCraft was occasionally breaking the time limit per frame in long games, so it had to go. I can’t find any practical disadvantage to the change. FAP is faster, smaller, simpler, more comprehensive, and less buggy. The CombatSimulation class responsible for calling it became tiny. Its results seem a little more accurate even in simple cases like unupgraded zerglings versus unupgraded zealots, and of course they are much more accurate for units that SparCraft does not support, like bunkers. SparCraft has the advantage of a basic understanding of terrain, so theoretically it might do a better job in assaulting ramps. But both combat simulators ignore vision issues and allow simulated units to pass through each other, so terrain effects are not well simulated anyway—the biggest difficulties in assaulting up a ramp are that you can’t see the top, and that not many units fit on the ramp.

• Fix some potential production freezes related to subtle interactions between the strategy boss and the building manager.

• Fix a potential production freeze related to ordering an impossible extractor.

• A worker sent early to construct a building is no longer prematurely swept up as idle. In the final test version, this was sometimes causing buildings to start a little later than they should have. It’s a recurring bug, and luckily this iteration was not as severe as the last.

• Turrets are a higher targeting priority for melee units.

• In ZvZ, don’t ever make hydralisks, and only make lurkers after hive. Steamhammer was always intended to play this way, and now the rule is strictly enforced.

• In ZvZ, deliberately undercompensate for enemy static defenses and expansions.

• If we’re making hydras now and planning lurkers later, maybe get hydra upgrades if there’s time. Steamhammer prioritizes researching lurker aspect, and the priority was too strict.

• If all lair tech looks useless, go straight to hive. Earlier test versions brought up a lair tech, either mutas or lurkers, even if they judged that all lair tech was unhelpful. Sometimes it’s better to stay on hydra-ling until you can get hive tech.

• More adjustments to what-counters-what. In general, more ultralisks and fewer lurkers.

• Several new zerg openings added with low probability. There are now 3 different 1 hatch lurker builds, even though there is still no 2 hatch or 3 hatch lurker build (all things in due time).

Other changes since the last release, by test version number:

• 1.2.6
• 1.2.5
• 1.2.4 (the long list)