Looks like Arrieta is running away with it. Perhaps that will change when all of the West Coasters check in. Here is a fun article about Arrieta's season, which begins with this:
Zero. Point. Seven. Five.
That’s become Jake Arrieta’s signature stat; 0.75 is the lowest second-half ERA in the history of baseball. Yet somehow it doesn’t capture just how dominant Chicago’s 29-year-old right-hander has been as of late. So, let’s try this instead: Since August 1, counting his four-hit shutout of the Pirates in the wild-card game, Arrieta has fired 97.1 innings, struck out 100 batters, walked 14, and allowed 46 hits, one home run, and an opponents’ batting average of .131. His ERA over that span?
Zero. Point. Three. Seven.
http://grantland.com/the-triangle/20...-chicago-cubs/
Note: I am a Brewers fan and am most certainly NOT a Cubs fan, I just like good pitching.