2 Resource Assimilators, both mining Tritanium 1 Resistance is Futile + Level 1 Nodes An opponent that is bad at scouting or an ally to help keep the opponent destracted! DO NOT BUILD A RECYCLING CENTER!
Sphere construction completion = victory, but with very limited Dilithium* Sphere construction destroyed = defeat!
After construction starts, make sure you send one of your miners to your Dilithium moon so that you eventually get enough Dilithium to continue building up your fleet.
Theoretically, the Borg can get 3 Probes and 4 Scout Cubes in 336 seconds, 4 Dodes in 352 seconds, 4 Adaptors in 356 seconds, or 4 Assimilators in 388 seconds. And that is ignoring resource consumption and multiple simultaneous vessel builds.
*During my testing, this gave me 22 Dilithium with a 3-regen, 1-torp sphere.