If your opponents hand is actually in the range you put them on 100% of the time then you must be assigning a much to wide of a range. However if your opponents hand is frequently outside of the range you assign then you are assigning a much too narrow a range. To take it to the extreme if you put your opponents on any two cards you will be right 100% of the time but that is not useful. If you are excellent at ranging opponents you should expect to be wrong some of the time. How often should you be wrong? Also, How do you know if you are near that frequency?