Let's start with, "What is it?"
Weighted Runs created. It’s basically a mix of slugging, OBP and BA. it,weights everything you do by how likely it is to produce runs.
The reason it’s great is because it’s standardized so that 100 is the MLB average. So if you see that someone has one of 117 it means he is 17 percent better than the average major league at creating runs. And if I tell you Mike Trout leads the Majors with 198 it gives you and idea at how good he really is.
And if I tell you Wieters has one of 64 and Lobaton 31 it gives you an idea of how those guys are at batting too.
It’s an easy way to compare hitters