Both players are capable of playing near-perfectly given their opponents range of hands. This is because poker is a game of imperfect information.

Mistakes happen in poker when players make a play that they wouldnt could they see the other persons cards. However, sometimes one players mistake will lead to the 2nd player making a bigger mistake (ie folding the best hand), which interestingly leads to the firsts players mistake not being a mistake at all.


Overall I think you are confusing what appears to be the best move and what is in reality (if you could see both players hole cards and tendencies) the best move.