The people who post on this forum can be so amusing.
Personally I classify skill as a degree of how much better someone is than me as a player (in standard), because I'm a perpetually bad player and any normal osu! player should pass me in skill level at some point. There is two types of skill: stream skill and jump skill. I'm not terribly good at either and my consistency and stamina is bad. I consider people as skillful if they can pass maps that I cannot pass. I find it especially impressive if they have the stamina to keep playing hard streamy maps with high consistency.
Modding Status: Inactive Undoing changes after testplay. Please support. Want a mod? Please leave me a PM, and if you are capable of modding I would prefer to m4m with you. I'll look at maps in any state/length and maybe in return you could mod one of my maps, I would appreciate it! I know how to time, but I'm not an expert.
I think he's trying to ask consistency vs potential. It's like comparing SnowWhite and rrtyui, SnowWhite is more consistent and would probably win in a multi room but rrtyui has set better scores and probably has more potential to set good scores, but lacks the consistency that SnowWhite has. At least this is what I've observed, maybe I'm not right but you still get the idea.
FC, because passing a song doesn't necessarily mean you did it well. Someone could've just about made it through the song by spamming through some segments (eg high bpm streams) and not actually paid attention to everything he did.