Bobby Wagner is good. Like really really good but this stat shows how great he really is.
For me, what this means is that he doesn't let blockers really touch him. He's agile enough to evade big bodies and still see where he needs to go. Obviously, he can then lay the wood on running backs when he gets to the hole. This is what you want out of an inside linebacker. You can also argue that the people around him are doing a great job of keeping him clean. Either way, they go hand in hand. He's great and his team is great.
Source: Pro Football Focus Twitter · Photo Credit: Keystone Press Agency