In my opinion, there's too much context that has to be accounted for in order to get fixated on a number, or average.
There's so much variance to the playoffs. Health, teammates performance, the opponent, etc. that in my opinion it's silly to use an average line as a means for evaluating someone. Dwight could average 15 and 14 and his impact on a game could supersede that which, if we were to average 20 and 15. You literally just never know when it comes to numbers. Impact, and effect on winning is more important that achieving such arbitrary lines like 20 points, or 15 rebounds, or 10 assist, or things like that.