I thought it would be helpful, especially for new players, to have a visual that shows what to expect from players at various skill levels. This visual would simply be a list of things that you as the community generally agree each rating should know how to do. Obviously this is totally qualitative and unscientific - people are overrated/underated all the time, and might be clueless about some things and better at others. I think it would still be valuable to have a checklist of niche things to improve performance and offer criticisms. From my perspective [1300], this is a quick list of things I expect from people of different ratings.
>300
Understands basic counters to each unit type
Knows how the Sup Com tech tree works
Understands how to perform most Sup Com functions like ground-fire, overcharge, upgrade, etc.
>600
Will cap mass extractors with storage at t2 eco
Will ping and communicate in chat
Will use mobile artillery to counter pd
Willing to expand out of safety of main base and seek map control
Will use adjacency bonuses
Emphasizes mobile units more than static defenses
Understands FAF jargon like "ASF", "PD", "Arty", "Mex", etc.
>800
Doesn't build useless firebases
Confident using ACU aggressively
Can make use of transports for drops and expansion
Makes use of reclaim fields
Can be expected to raid during early game
Can handle two theaters of war
Understands basic meta for overplayed maps
Has build templates prepared for mass storage and walled pd
Will kite enemy units
Has router ports forwarded for FAF
>1100
Has general build orders to avoid stalling early on any map
Knows how to micro ASF
Diversifies army composition
Will make adequate use of scouting
Can concentrate in multiple theaters of war
Can effectively continue to eco during late game
Will micro individual units to maximize battlefield impact
Not overconfident in experimental units, and supports them with flak
Will create teleport defenses around sensitive structures
Avoids overbuilding power
Makes use of spread attack order
Can hover-bomb
>1300
Practices map-specific build orders to give a speed advantage
Enough gameplay understanding to anticipate potential snipe attempts without intel
Good target prioritization
Will recycle obsolete structures and units back into economy by self destruct and reclaim
Won't leave idle engineers
Knows (by heart) the damage stats of common things like strat bombs/mercies/percivals/nukes/etc.
Knows (by heart) the costs of common things like engineers/t2 mass upgrade/ACU upgrades etc.
Can confidently time transitions between t2 and t3 factories/eco while being pressured
>1600
Optimizes play with hot-keys
Customizes strategic icons
Lives somewhere in Europe
Has their number pad completely filled with taunt keybinds
Calls Othuums "Slippers" like a nerd
Let's discuss what's reasonable to expect from your random teammates or ladder opponents. Is there anything in particular you would add or move? The ratings I listed are arbitrary.