Because it seems like a lot of the discussion so far here about WAR, & specifically its use of UZR, really is calling for a defensive stat that depicts true talent. Please correct me if I'm wrong, but that's the general sense I'm getting. And I think if that's the kind of stat that people are after, I'm not sure it can be found. Probably not. At least not with one year of data. The number of chances will always be a problem with defensive stats even with perfect inputs. With perfect inputs though it would tell you about how many runs saved or lost over a season. FieldFX would help with that but it may not be publicly available anytime soon.