In 2016, the Cubs had the second-best rotation in baseball (by fWAR). Their starters’ ERA was 2.96. They threw the second-most innings in the league, yet allowed the sixth-fewest home runs. Three individual pitchers were among the MLB’s 25 most valuable.
This year’s crew is not as good as that one.
But it’s the best since then.
Entering play today, Cubs’ starting pitching ranks ninth among all MLB teams in fWAR, after ranking twelfth and 16th in 2017 and 2018, respectively. Its ERA is 3.96. It started the second half with six straight quality starts, and while each of the arms have had their struggles at times, as a unit, they’re a big reason why the team’s in first place.
An interesting corresponding metric, as the Mike Montgomery era comes to an end, is how many starts have been made in each of these four years by Montgomery and other non-designed starters (i.e., not in the rotation by design). In 2016, there were ten such starts. almost all bullpen games: five Montgomery starts and one each by five other pitchers. In 2017, there were 26 such starts: Brett Anderson was a planned part of the rotation, José Quintana was acquired midway through the year, and Montgomery and Eddie Butler filled in all the other outings but one. Last year, there were again 26 of them: 19 by Montgomery and seven spread over five different pitchers, with Tyler Chatwood a planned starter and Cole Hamels acquired midway through the year. To date in 2019, there have been only six.
In other words, part of why the Cubs’ rotation has been more effective this year than the last two years is simply that the guys designed to carry the load has been able to carry the load. Beginning with the 2016 season, the Cubs have only “missed” on two of their ten planned starters: Anderson and Chatwood. I don’t know how this rate compares to those of other teams, and it seems, from looking at all this, that starting pitching depth has been an issue (especially when comparing the Cubs to a team like the Dodgers, for whom seven pitchers made 15 or more starts last year, all with both FIP’s and ERA’s under 4.00), but it pins down the question of rotation success to one variable: health. When the starters have been healthy, the rotation’s been solid.
Cross your fingers.
