Instructions
Download Star Craft 2 map editing software such as SCMDraft.
Create a new map and establish the borders of that map with the smallest dimensions possible.
Set the base starting locations for all players right next to each other, but be sure to leave a bit of room for base expansions. Placing bases one screen-length apart should be appropriate.
Surround each base with yellow crystals and at least eight vespene geysers to enable the fastest resource collection possible.
Clear the terrain between all of the bases so that there are no obstructions whatsoever. Armies will be able to take the fastest route possible to bases with this setup.
Avoid placing neutral creep that will slow down armies.
Save your map and upload to the "Star Craft 2" custom maps.