
Only teams like the 2006-2010 Nationals want that out of their front line starters.
Just checked and in 2014 Roark was top 15 in ERA, FIP, and WAR for NL starters. In 2014, he had the 13th best WAR in the NL. Four different teams (Cards, Pads, Dodgers, Nats) had two pitchers with better numbers than those, with ERA and FIP being about same. The Cardinals, Padres, Dodgers, and Nationals (Stras/ZNN) all had some darn good pitchers. Roark was right there.
He is a midrotation starter for the Nationals, but more than half the NL would have been happy to have a starter with Roark's production in 2014 as their #1 and definitely their second starter. His arsenal looks weak when he pitches, but more often than not he gets the job done.
And this season he isn't top 15 in those but he's a good start or two away in each. It will be hard to match those numbers from 2014 but for now he is near the top in everything. We'll see once sample size continues to grow. Being able to slot in a Tanner Roark as your #3 or #4 guy is how you make a run at 100 wins.