Depth gives Dodgers' rotation luxury of skipped starts

Starters' 3.95 ERA ranked sixth in MLB last season

February 17th, 2017

Rich Hill is going to miss some starts in 2017. So, most likely, will , , , and just about every Dodgers starter you can name. This is a team that set a Major League record for most trips to the disabled list in 2016, and at one point in August, Los Angeles actually had seven -- seven! -- starting pitchers on the disabled list simultaneously. Most of the same group returns. Missed time is inevitable.
But what if that's not a bad thing? What if it's actually part of the plan? What if the total number of trips to the disabled list not only doesn't matter, but actually matters less than it ever has?
This all sounds like an odd way for a team that's at least in the conversation for being baseball's best club to go into a season, we grant. But it's a reflection not only of the unparalleled rotation depth of the Dodgers, but of the evolving way in which teams approach how to best soak up innings -- and how a quiet 2017 rule change could aid a team that's set up exactly like the Dodgers are. A deep, talented group with injury concerns isn't a bug, is the point. It's a feature.
To understand what the Dodgers are doing, it's important to understand that putting together a starting rotation is no longer about finding five pitchers who can give you 32 starts and 200 innings apiece. The question these days is simply "What's the most effective way to get around 920 quality innings from your starters?" Which is roughly the average that we saw from Major League rotations last year. Whether that pie gets sliced up among six pitchers or 12 doesn't really matter so much, as long as: A) they're good; and B) you have roster flexibility. 

That's another way of saying "We're happier getting 120 good innings from Pitcher A and 80 good innings from Pitcher B than 200 mediocre innings from Pitcher C," even if it means both Pitchers A and B spend some time injured. Rather than discard the talented pitcher who may not be able to hold up all season long, the better strategy is to get what you can out of him and have someone else skilled ready to go. 
But aside from the difficulty of collecting enough talented pitchers, there's two reasons that this kind of strategy hasn't been easy to implement in the past, and they're both related to roster construction. The first is that in order to swap guys in and out over the course of the season, you need to have a few of them with Minor League options remaining, and the Dodgers do. Of the 10 rotation candidates with Major League experience, six (everyone but , Hill, Kazmir and McCarthy) can be sent back and forth as needed. We saw this in action last year, as Maeda was briefly "sent" to the Rookie-level Arizona League in a paper move in between starts so could throw five scoreless innings against the Cubs.
The second is that as part of the new CBA, the 15-day disabled list has been cut to a 10-day disabled list. We took a detailed look at the implications of that move in December, with the takeaway being that certain teams might be more motivated to be more aggressive with the disabled list, especially during spans with a scheduled day off. Why let a roster spot languish unused for nine days when a particular starter may be scheduled to pitch just once? Why not use it as something of a "rest zone," given the increasing emphasis teams are placing on rest and recovery?
That alone is likely to cause DL trips to increase, which is another reason not to judge a pitching staff based on that number. So how do you cut that pie up? Let's take 920 innings and theoretically divide that up among the prospective Dodgers starters. One potential application could look like this -- plus, in some cases, more out of the bullpen:
200 -- Kershaw  
160 -- Maeda 
140 -- Hill  
110 -- Kazmir            
100 -- Urias               
90 -- Wood 
80 -- McCarthy  
10 -- Ryu  
40 -- Others            
Maybe that's unsatisfying. Maeda, after all, threw 175 2/3 innings and is talking about wanting to hit 200. A mere 110 innings from Kazmir would be his fewest in the past few seasons and doesn't feel like a great return on $48 million. If Alex Wood is as good as he was before he got hurt, you want to see much more of him. (We're guessing on McCarthy and Ryu; it's nearly impossible to know what to expect.) But then, realize the potential effect here. Both Maeda and Kazmir got off to good enough starts, and declined as the year went on:

What if skipping the non-Kershaw pitchers allows you to avoid some of those later starts? What if all the flexibility lets you keep Maeda on five days rest (.586 OPS, 3.01 ERA in 13 starts) rather than four (.728 OPS, 3.97 ERA in 13 starts)?
Or let's take Hill, for example. If your expectation is 30 starts, then your expectations are too high. (If he could be counted on for that, he'd have cost more than $48 million, anyway.) Over the past nine seasons, Hill has made eight trips to the disabled list and thrown 292 1/3 innings. While he's been elite when healthy since 2015 (2.01 ERA), that's roughly 36 innings -- or slightly less than Kershaw threw last April alone -- for every trip to the DL. Hill will be 37 next month, and he got hurt twice last year, injuring his groin and struggling with a blister. We're not telling you anything you don't know.
So you don't expect Hill to make every start, and one way to do that is to simply let him go until he breaks down. But what if that wasn't the plan? What if the Dodgers wanted to say something along the lines of, "We just want four good starts per month from you," which over six months and an average of six innings per start would be 24 starts and 144 innings?" That would already be Hill's most since 2007, and seems like a reasonable expectation.
You could apply such thinking to everyone other than Kershaw, who expects to get the ball every fifth day. It's unconventional, but then, so are the Dodgers. The number of DL trips doesn't matter. The number of quality innings does. No rotation in baseball is as well-prepared to deliver them -- even if it's from more pitchers than you may expect.