For example, you are replaying the 5th hand you played with an opponent where he was 0/0/0 at the time. It would be useful for there to be an option in the replayer so that you could view the stats up to the hand that took place. So in this case, stats from hands 1,2,3 and 4.
I am aware of the "use stats up to day of hand" option, but this still isn't accurate enough if you were to play more hands during the day with that opponent after the hand you are viewing. For example, if you played 200 more hands with him where he became 52/47/10. It would be inaccurate to use those stats to analyze hand 5.