I usually have a decent understanding of the games themselves. I get the meta and why it's played and what's happening and I can apply that to my play, and I don't really have performance nerves exactly. I mean, like anyone in a one-hit scramble or ultra close set I'll get wired up pretty good, but issue isnt nerves, so much as nerve damage.
My hands are shit. 15years as a fighter on top of always having worked with my hands have left them in bad shape. I have weak bones in my hands, always have had and have had 14 or so breaks over the years between just life-accidents and damage from boxing/mma stuff. Then the raccoon thing on my left hand, lol.
It's difficult to explain exactly but they are stiff as boards and seize up snd shake a little sometimes, and the manual dexterity I used to have is kind of a pipe dream. The closest analog I can come up with is imagine if your controller or stick's buttons and dpad moved very slightly, and the pressure to push a button changes very slightly. Its weird, but thats the best I can do to explain it. I can 'beat' it though through crazy long repetition and time I can just dig it so far into muscle memory that it'll work most of the time.. but that takes me a lot longer than some people - not everyone though.
/end whining rant. Just kind of explaining why I sort of obsess over execution sometimes.