Bull .
This must clearly a conspiracy by the good people at NBA.com/stats
these numbers are fairly consistent for several seasons (his post defense), it isn't some manipulation. It really annoys me when someone has an opposing view and then attacks the credibility of an advanced stat on the merit that it doesn't gel with their opinion which, may be wrong to begin with. This is exactly what "BAAM" does.
He defended Randolph and Howard as well as anyone. Randolph looked frustrated in the WCF. This really goes without saying in today's NBA, which shocks me that I actually have to but defense isn't just measured in blocks and steals. As I mentioned before, there aren't a ton of great post players in the league. That being said Bonner, for 10 minutes can step in a play solid post defense.
Offensively, the Spurs generally are difficult to stop when he is on the floor, whether he is hitting 3's or not. Teams have to expect he will hit a 3 if left open.
The Spurs actually exclusively had Bonner set screens for Parker, in hopes of exploiting Randolph's defense. Forcing him to step out 24 feet on Bonner after the roll or have to keep Parker in front of him.
I also mentioned that he does struggle with teams with athletic big men (like Denver) he gets a bad rap on that side of the ball. Is he better defensively than Duncan, Splitter, or Diaw? of course not. But he can be effective.