Chicago Cubs: Rest – could it ever be a bad thing?
Perhaps the most obvious advantage of going with a six-man rotation is the extra day of rest each pitcher gets between starts. In the case of the Cubs, this particular advantage carries an additional allure.
Jon Lester is 34 years old and has a lot of mileage on his valuable left arm. His career splits are quite similar when comparing his starts after regular rest to those where he was given an extra day. In 2017, however, Lester’s ERA was over a run and a half lower with additional rest. This is a promising trend if looking to extend his value year over year.
Beyond Lester, the rest of the staff is somewhat of a mixed bag, but a case could be made that the extra rest wouldn’t hurt. Both Jose Quintana and Kyle Hendricks have substantially better strikeout-to-walk and WHIP numbers when getting the extra day of rest. Tyler Chatwood was very bad in 2017 with the additional day. However, 2016 he was more than half a run better in those same situations. It may well be the 2017 splits were impacted by a number of starts in Colorado, where Chatwood rarely pitched well.
Darvish is the outlier here. All of his stats – with the exception of strikeout rate – are worse with extra rest. That said, the start to his Cubs career has been a bit shaky, so there’s reason to believe adjusting his routine may do some good.