Bobby Fisher during his legendary 20 game winning street was at 72%. So he only match the computer for best move 72% of the time Magnus Carlson playing at his best is 70%. Gary Kasparov in his career was 69%, then the super GM's category are typically in the 64 to 68% range. However look the idea that Hans Neman is in the 70s 80s or 90s during tournaments would be just off the charts level of play and if if he's not cheating then we should expect over the next couple of years that he should rapidly become the world number one player over the board.