This is a true phenomenon in sports. On a certain day, I once shot way below my average in golf. Every putt dropped, every drive was true. When I played handball and squash and racketball in my younger days, on rare occasions I had a perfect day.
It is rare, and sometimes, more often, the reverse is true and nothing works. I’m convinced it has something to do with how the nerves and muscles and psyche and all the rest work in sync that day, or more often out of sync. Feeling blah or on fire.
There is most likely some battery of tests that, if done before every game, would correlate with a game being hot, average or cold. Don’t know why nobody (to my knowledge) has done that.