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Here’s a different solution to the rotation

Would piggybacking starters work to the Phillies benefit?

Miami Marlins v Philadelphia Phillies Photo by Rich Schultz/Getty Images

The Phillies have an interesting dilemma coming into 2019 with their starting rotation. They simply have too many options to go around. We’re not here to debate the quality of those options as far as subjectivity goes, but it is an interesting concept to look at. With all of the options the team has, outside of simply sending some to Lehigh Valley, is there a way to solve that dilemma by “piggybacking” two starters together? It’s an outside-the-box idea, once with some potential and also some pitfalls, but it does have some merit in theory.

The natural issue we find is that piggybacking is an experiment used with pitchers that usually is done in the minor leagues as a way to keep innings and pitch counts down. It’s not often performance-related. The Astros were famous for deploying this strategy in their system a few years ago. It’s never really been done in the majors, even if you wanted to count “The Opener” as piggybacking. Even then, the reliever starts the game and gives an inning or two, not much more. Here, we’re asking each pitcher to give 3-4 innings if needed.

While it might seem counterintuitive to suggest burning two starters on one night, in theory, you can ask those guys to come back a day or two sooner if needed as long men or a guy to give you an inning. It’s not preferable because of the nature of starters, with their daily schedule and whatnot, but in theory it could work.

If we’re going to look at this with the Phillies, let’s begin under two assumptions. First, Aaron Nola and Jake Arrieta are not going to have any starter piggyback with them. Nola is an ace and does not require one; Arrieta is a veteran capable of going 6+ innings with regularity (reminder: I’m not going to go into the quality of those innings). The second assumption is that Nick Pivetta has all but wrapped up the third spot in the rotation. We’ve seen many pieces this offseason written about the possibility that Pivetta is the member of the rotation most likely to break out and have a huge year. It’s probably safe to assume management feels the same way and will not alter his routine at all. So who does that leave us with? Jerad Eickhoff, Vince Velasquez and Zach Eflin, that’s who. These are all quality rotation options that can help the team win.

The first thing I want to do is assume full health for each pitcher. Assuming this is true for Eickhoff is a stretch, but judging from his final start in the 2018 and the fact he hasn’t had any issues this offseason, I feel safe in making this assumption. So, if all three pitchers are healthy, which two should go together?

How did they do during the game?

Let’s first look at their effectiveness in sections of a game and see if it is obvious which two pitchers should be put together in our thought process. For Eickhoff, they will be his 2017 numbers.

Effectiveness by inning

2017/18 Eickhoff Velasquez Eflin
2017/18 Eickhoff Velasquez Eflin
Innings 1-3 .260/.342/.432 .248/.332/.448 .270/.332/.470
Innings 4-6 .291/.339/.432 .238/.308/.359 .249/.306/.381
Innings 7-9 .538/.563/.923 .412/.500/.588 .241/.267/.414

Strangely enough, this is not what I was expecting. I didn’t think the two pitchers I would have grouped together would be the worst pairing. When I started thinking about this, I would have thought that Eflin and Velasquez were the better pairing for this idea since they seem to be natural fits. Our subjective minds believe that these pitchers get worse as the game goes on because that has become a familiar refrain among analytics buffs. The more times a lineup sees a pitcher, the better than lineup will do. It has led to the rise of The Opener and the drop in innings from starters. Yet looking at the evidence from 2018, the first year these two were healthy starters for the entire season, suggests Eflin and Velasquez buck that trend. Both pitchers seemed to settle in as the game wore on, seeing their effectiveness get better in the middle innings. For Eickhoff, it’s a little more difficult to tell because his 2017 season was so different from the previous two that assuming he was injured is a safe line of thought. Getting back to Eflin and Velasquez, I started to wonder why. Why are they better? Does Eflin, who is often called a natural sinker baller pitcher, get better because his stuff moves more? Does Velasquez calm down and allow his stuff to have better movement as well?

Eflin’s stuff

From what we hear and read about Eflin, his sinker is used often. “He’s a groundball pitcher!” is a common refrain from pitchers who use a sinker, and the common thought would be that his sinker would have more movement with a drop in velocity. That, in turn, would let him be a better pitcher later in the game when he is theoretically more tired. Well, I got news for you: that ain’t exactly true. If you click here, you see that his stuff, on average, actually didn’t lose much velocity during a game. When it comes to the movement of his pitches, even then there is hardly a difference. Even his sinker, the thing he throws most often, only loses about 3/10 of an inch as the game wears on.

Granted, 3/10 of an inch is usually all a pitcher needs to induce the batter into driving a ball into the ground, but his groundball rate of 41% doesn’t exactly scream “groundball pitcher” either. Perhaps the issue is that we need to redefine Eflin not as a groundball pitcher, but someone who is pretty much neutral, just as capable of inducing a ball on the ground as in the air. He’s started throwing a regular ole’ four seam fastball more often. Is that someone you’d like to see go with another pitcher?

Velasquez’s stuff

With Velasquez, it’s kind of more of the same. As he went through a batting lineup, he held his velocity rather well, surprisingly well. The movement of his pitches didn’t have much of a change either.

Similar to Eflin, he just maintained whatever he was doing throughout the game as he went through the lineup more than once. It’s kind of weird and goes against the school of thought that as pitchers get tired, their stuff will move down in the zone more often.

These data points I found from these guys suggests that perhaps they shouldn’t be paired together. They don’t really have dissimilar profiles anymore and pretty much do the same thing. It kind of knocks down the thought that the team has two pitchers already here that naturally would fit together in this kind of rotation experiment. Is that enough to entirely throw it out the window? Maybe, but we’d also have to consider Eickhoff as well. The problem with him is that the data available is over a year old and prior to an injury. Will all that stuff he has still play the same? Does he have different stuff now? Unfortunately, I think we need a full season of health from Eickhoff in order to see if he is someone who could use a piggyback pitcher.

As I stated at the beginning, having two starters go together in one game, going 3-4 innings a piece is great in theory. Unfortunately, it may not be practical for a team like the Phillies. They don’t really have two pitchers who go together naturally. So if we were to look for an outside of the box option to the team’s abundance of starters, the best solution is probably to use the minor league options still available to the three starters (Velasquez and Eickhoff have 2, Eflin has 1) to get them all the innings they need for their development. Hopefully, we can see all three take a step forward in 2019.