what if his moves are all only good not best, that would be smth to test
high accuracy games 70% or higher

"good" is fine, for most, and would be fine as long as he is consistently playing them, as that would be his way of playing consistently.
Also "good" could mean best, excellent, or good, I just didn't want to say all of that in the beginning.

yeah but good means best/excellent/good, good is just a shortcut to say of all them.
For example, remember what Bobby Fischer said in a quote "all that matters on the chessboard is good moves"! Of course he didn't just mean good moves, he mean't best moves and excellent moves and brilliant moves, but he just said good moves to cover all of that...

https://www.chess.com/game/live/33565156853 88.3 by me
*if a player consistently makes good moves...*