I doubt that anyone here looks at one number. I assume most open up a player page and mentally assign weights to various different numbers to get a feel for how a given pitcher is performing. Gut feel, vetrin presents, years of experience and all that. Scout dat fangraphs page.
Yeah, we've definitely been pulled back from the days of thinking pitchers only control BB, K, and HR rates. But it seems like there are more ERA-DIPS outliers this year than I ever remember there being before.
Yeah, that's actually possible. I'm not really inclined to cut anyone from my farm for a relief prospect though. And I'm not sure Montas has the breaking ball to be truly elite.