What Is Up With the Cubs Rotation?
After getting swept by the New York Yankees and losing two out of three to the Colorado Rockies, the Chicago Cubs are now sitting on a .500 record. By run differential or BaseRuns expected performance, tools that strip out sequencing, the answer is the same; the Cubs have played pretty much like a .500 team. The offense has been a little worse than average, the pitching a little better than average, but overall, the team has played roughly like an 81 win team so far.
Of course, this isn’t what recent Cubs teams have played like.
In 2015 and 2016, Cubs starters topped all of Major League Baseball with 36.3 WAR, just ahead of the Nationals, Mets, and Dodgers. The starters’ 3.50 FIP, without even considering the impact of defense or the potential of inducing weak contact, has been the best in the majors. The Cubs have returned almost all of last year’s staff intact, with Jon Lester, Jake Arrieta, Kyle Hendricks present for each of the past two seasons and John Lackey around last year.
The question we are trying to answer here is what is responsible for the downturn in results. We are just 34 games into the season, so we could chalk it up to luck. We could try to determine if the talent level has changed in any way, which might cause us to lower our expectations, and we could point to some outside factors that aren’t luck, but aren’t necessarily the responsibility of the pitchers, like defense. To frame our understanding of what is going on, it probably helps to create some expectations of what we would expect to see from a Cubs rotation this season. While Brett Anderson has made six starts, he’s only pitched 12% of the Cubs starter innings, and little was expected of him, so we will focus on the four returnees. Read the rest of this entry »