dWAR is an analytic that is derived by a special group of nerds who ( allegedly) watch every pitch of every game and , with their expertise , come up with a stat known in the business as Ultimate Zone Rating or UZR for short. Then, using a secret formula , that is converted into dWAR , defensive wins above replacement , which basically tells you how many games a given player wins or loses on defense as opposed to the average jabroni. It is not clear just who these special nerds are or if they are doing this voluntarily . But it is all very scientific. So, don't depend on your eye test , instead go with UZR , which is essentially someone else's eye test.