This phenomenon is being referred to as ‘the zone’
Ever had that feeling of playing on auto-pilot, very well, and as soon as you realise you start playing badly?
Your alpha brainwaves will spike when you are in ‘the zone’ and you will gain unbelievable skill, I have been doing this and the results have been great, just yesterday I pulled off a 4-man ace (5v5) in CS:GO something I have never done, using this method.
It's the same as how your brain works automatically e.g. moves all you muscles without doing them individually.
HOW TO Flow State