The correlation between fWAR (Fangraphs WAR) and actual wins is very strong. There are always outliers, teams who outperform or underperform their cumulative fWAR but the relationshisp is strong. Whatever fWAR misses in terms of individual players does seem for the most part average out over a group of players. That being said there are pitchers who seem to consistently outperform or undeperform their peripherals. When this happens you'll see a big discrepancy between the more peripherals bases fWAR and the more results based bWAR. Nolasco is just such a case. He's been worth 10.8 Wins over his career by bWAR and nearly twice as much by fWAR (20).
So this is an interesting case. If you are a fWAR purist, you think Nolasco is basically a three win pitcher and that his batted ball numbers should regress to league norms and stop inflating his ERA. Alternatively, you could believe that Nolasco is basically a fWAR breaker, a guy who will always underperform his peripherals and is basically a no more than average pitcher whose nice K/BB numbers are undermined by an unfortunate tendency to give up good contact.