D.o.s., I see this pretty frequently on this forum. An article will share a variety of stats that paint a picture. IN this case, several articles all over the internet paint a picture of Biyombo as an elite level rim protector who could be a great fit here. It uses a variety of stats to give context to that statement. People then respond by trying to discredit the stat. Seems like a waste of time. Instead of using your efforts to discredit the stats, how about you find a defensive stat that you actually respect and tell me how Biyombo fares. That's way more interesting to me. In a conversation about Noel, Roy Hobbs conceded that Noel put up some impressive defensive stats, but then Hobbs found some even more obscure defensive stats to suggest Noel still needs work (he probably does). I thought that was interesting.
If you disagree that Biyombo can be a needed addition here based on his ability to protect the rim, show me why.
I personally don't have a defensive stat I lean on. I'm actually not that in depth as a fan. I mostly just relay what others are saying. Seems some people put some faith in defensive rating. I see that Biyombo had the best defensive rating on his team (99) for two years running. Oddly he had the best offensive rating on his team as well (115). The player with the best defensive rating on the Celtics this year (discounting Shavlik and Powell, who only played brief minutes in a couple games) were Rondo (101), Olynyk (103) and Sully (103). Bit strange that Smart (104) and Bradley (107) weren't better, but maybe the stat favors bigs. Zeller's defensive rating was 105.
Biyombo's rating of 99 would have put him Top 10 had he qualified. Here's the leaders:

Maybe that stat is worthless (it's filled mostly with names I'd expect to see there, but it's odd that Big Al is so high considering all the other stats point out how much better Biyombo was as a defender). Maybe that stat is broken. What's a better one?