I disagree, I don't think they undervalue rebounding at all. In my association I have nothing but great rebounders in my starting lineup because I was finding that I was getting destroyed by opposing teams that were good at rebounding. I think the reason Wall may be rated higher is because he has higher ratings in more categories than Blake. For example, I'm sure Wall has higher quickness, stamina, injury, speed, steal, assists, shooting, etc. So while Blake may be much better at rebounding, low post scoring, dunking, jumping etc., Wall is a higher rated player in more "other" categories. Don't get too caught up in ratings though, they're just a number. I have guys on my team starting with overall ratings in the 60's while I have 70's guys on the bench, it's all about getting guys in there that fit your needs.