Starcraft AI blog

Registration for the AIIDE 2020 tournament opened today. The registration deadline is 31 August, and the submission deadline is 30 September. Steamhammer will be competing.

Most details seem to have no change from last year, but after using the same 10 maps from 2011 to 2019, this year there is a new pool of 10 maps. In the 2 player maps, Benzene is dropped in favor of Polaris Rhapsody. In 3 player maps, Tau Cross is out and Longinus is in. In 4 player maps, Andromeda and Fortress give way to Fighting Spirit and Roadkill. Other maps remain the same.

That’s 4 new maps. All 4 appeared in the “unknown map” secondary tournament last year, so they are tested in bot play. (That tournament ran with 5 maps; only Arcadia was not moved into the new map pool.) All the choices seem standard and conservative, unknown only in the sense that they were unannounced beforehand. By the way, the “unknown map” tournament will be repeated this year. Maybe the map choice will be a little more daring this time?

• (2)Destination Back door mineral block to each main base, and other features favoring cheese play. The most logical third base location is immediately above a wide ramp and hard to defend; bots have even more trouble defending the thirds.
• (2)Heartbreak Ridge Back door mineral block to high ground over each side’s natural base, on the path to the third. The many ridges benefit bots which understand high ground. The center base breaks the middle of the map into two paths; you can go above or below the center.
• (2)Polaris Rhapsody Follows the three-paths map pattern; you can move your army down the center, or by a longer path down either side.
• (3)Aztec Low-ground main bases. This causes problems for bots which wall off inside their main.
• (3)Longinus Level-ground main bases, like Tau Cross which it replaces.
• (4)Circuit Breaker is an old standard.
• (4)Empire of the Sun is another map with level-ground mains.
• (4)Fighting Spirit is another old standard, likely the most played map of all time.
• (4)Python is an old map which I take to be an attempt to rework the aboriginal Lost Temple into a balanced map. Compared to most maps, there is more contrast between close and distant main bases; the enemy may be near or far depending on starting locations.
• (4)Roadkill is the most recent of the maps, not to be confused with Roadrunner. It has low-ground mains and the famously thorough Freakling technical design.

Maps not in the SSCAIT pool are Polaris Rhapsody, Aztec, Longinus, and Roadkill. The maps are also outside of BASIL’s extended map pool (“2019Season1”), so some bots may not have played them.

The changes seem designed maintain the variety and balance of the map pool. I don’t expect any big shift in results; a tournament on the previous map pool would likely have a similar outcome. The new pool is slightly less tricky due to dropping Benzene and Fortress, on which a bot with specialized map knowledge has a chance to gain an advantage. That may mean that old bots and new bots with more specific skills can be compared a little more fairly, but I expect that the difference is small.

Overall the map pool change seems fine, unlikely to cause difficulties either in the tournament or in comparing with past tournaments. Given that, I wonder why the change was made. For my part, I’m pleased to see Longinus. I will miss Fortress, though. I like that map.

Update: I asked Dave Churchill why the change after so many years of the same maps. He said he just hadn’t gotten around to it before—the maps were originally meant to be changed every year.