Pitcher Pairing Party

The Mariners’ rotation is starting to resemble the group that will guide the team through the second half of the season and (hopefully) into the playoffs. The addition of Andrew Moore was as fruitful as it was exciting, and Felix Hernandez’s return adds at minimum two capable starting pitchers to a staff that was lacking in that department. While a rotation featuring Felix, James Paxton, Ariel Miranda, Moore, and Sam Gaviglio is far from the worst the Mariners have rolled out this season, it still doesn’t inspire overwhelming confidence in the rotation. The Mariners are in the bottom third of the league in innings pitched per start, and even the healthy returns of a few pieces is unlikely to change that.

The reality of this is, even with the rotation getting healthier, a hefty portion of the Mariners’ success going forward will fall on the bullpen. Thus far that group has the sixth-highest FIP in baseball, so that’s far from reassuring. Even with late inning guys like Edwin Diaz hitting their stride recently, the brunt of the pressure falls on middle to long relievers. If the starters leave the bullpen four innings of work, someone, or some combination of people, will need to bridge the gap from starter to closer. Our mission here is to find which bullpen arm best pairs with each starter, giving the Mariners the best chance to get to the eighth and ninth innings with their lead intact.

It’s tougher for batters to adjust to subtle differences between a pitcher and a reliever. For example, if the hypothetical starter throws a reliable sinker and a solid slider from the right side, but doesn’t throw very hard, it would be more difficult to adjust to another righty with a similar arsenal throwing from a different arm slot than it would be to adjust to a flame-throwing lefty. With that in mind, let’s pair some pitchers!

First, we’ll take a look at Felix. For the majority of his career, the King has loved to throw his sinker early in counts and use his changeup as his primary secondary offering. Surprisingly, the pitch he’s used most with two strikes his whole career is his four seamer. That tendency has been even more exaggerated this year.

One reliever that would pair well with Felix is Steve Cishek. The similarities between the two include their tendency to start with their sinker and the areas of the zone they like to attack. Both pitchers tend to operate in the lower part of the zone while targeting the outer half of the plate, regardless of the handedness of the batter.

Here’s Felix’s Zone Profile from Brooks Baseball:

Now here’s Cishek’s:

The two differences are obvious. First, Cishek’s delivery is dramatically different than Felix’s. Additionally, Cishek throws his slider with two strikes, while Felix hardly ever throws his slider at all; however, the fact their primary offerings and pitch location tendencies are similar, the difference in location and repetoir should be enough to keep hitters off balance for at least an inning.

An additional upside to Cishek is that he has experience in middle relief. In 2011, 14 of his appearances lasted longer than an inning, with his longest outing lasting three frames. In fact, just last year he pitched in 10 games for longer than an inning of work. His longest appearance this inning was an inning and two-thirds of scoreless baseball against the Rockies. He’s occupied a role that’s required multiple innings in the past, and is capable of fulfilling that requirement again.

Replacing Cishek with Vincent in or around the eighth inning would complete the next step in the progression. Both pitchers sit around 90 MPH with their fastballs, and use a similar out pitch with two strikes. Cishek uses his slider nearly half of the time he has two strikes, while Nick Vincent uses his cutter (Brooks Baseball classifies it as a cutter, but I’ve seen it called a slider elsewhere) over half of the time in two strike counts. Vincent’s slider is much faster, and breaks differently than Cishek’s slider. The difficulty in transitioning from Cishek to Vincent lies in adjusting to the difference in offspeed offerings.

Ideally, a start made by Felix followed by appearances from Cishek and Vincent should get the Mariners into the ninth inning, where Edwin Diaz can do his work; however, if Felix’s start runs short, and neither of the two can take on more than an inning of work, the option of using a reliever like Marc Rzepczynski may prove useful. Although there are no similarities between the aforementioned pitchers and Scrabble, a lineup that’s faced Felix, Cishek, and Vincent likely has a lot of lefties, in which case Scrabble can come in and do his thing.

Finding an ideal pair for James Paxton is a little tougher. Very few pitchers share similarities with the massive lefty who throws in the upper 90s with a devastating knuckle curve; however, one James Paxton tendency lends itself to a couple similarities with James Pazos. Beyond sharing the same first name, both Paxton and Pazos throw their fastball more than 65% of the time. Their average velocities on their fastballs are within 0.50 MPH; however, Pazos’ fastball has quite a bit more arm-side run, while Paxton’s fastball has more “upwards” movement.

Here’s Pazos’ scatter chart of pitch movement (also from Brooks Baseball):

Compared to Paxton’s:

Additionally, Pazos’ slider and Paxton’s cutter have similar horizontal movement, but Pazos’ slider drops more and is much slower.

An unorthodox replacement to Paxton is Max Povse. Povse hit 96 MPH in his MLB debut twice. His velocity spike could be a result of nerves, or maybe his transition to the pen allows him to put more behind each of his throws. Regardless, if he’s sitting in the mid 90s with his fastball, he could be an effective replacement to Paxton. We’re working with a small sample size here, but it also looks like Povse isn’t afraid to pound the inner half of the plate. Here’s his strikeout of Ian Kinsler from his debut:

Paxton and Povse are both are capable of attacking the inner-third of the plate with hard fastballs from absurdly high release points.

Sam Gaviglio is a sinker-slider pitcher who lives in the bottom of the zone, while targeting the outer-portion of the plate. In terms of arsenal and zone profile, he’s a near identical match with Steve Cishek. Following Gaviglio with Cishek would require hitters to adjust to seeing similar pitchers from a much different arm slot.

Continuing this progression, Tony Zych fits the bill of spelling Cishek later in the game. While Zych’s primary offering is a four seamer, not a sinker, his throws leans heavily on his slider later in counts. Surprisingly, even though he comes much more over the top than Cishek, Zych’s slider has more similar horizontal movement to Cishek’s (in fact, maybe even a little more). Also, his slider dives more than Cishek’s.

Hitters adjusting from Cishek to Zych would see a slider with similar horizontal movement with more dip, while also needing to adjust to a similar pitch sequence coming from a different arm slot.

If the Mariners still needed one more pitcher to reach the ninth and allow Diaz to shut the door, Nick Vincent is the natural choice for this group of slider hurlers. Vincent and Zach have very similar release points, and offer the same fastball-slider (although Vincent’s is classified as a cutter) progression. Vincent’s cutter, however, has more of an “upward” break and does not move as much horizontally. Fittingly, if Gaviglio, Cishek, Zych, and Vincent can get you to the ninth, Diaz will also come in boasting a fastball-slider arsenal with his own fiery twist.

Andrew Moore’s sample size, obviously, is very small, but what we’ve seen from him is high dosage of fastballs, with a good changeup, so-so curveball and slider as his secondary offerings. Replacing Moore with a pitcher like Dan Altavilla later in ball game would force pitchers to face another fastball-first pitcher throwing from similar vertical release points. The adjustment hitters would have to make, of course, is the speed. The jump from Moore to Altavilla is substantial, and would be a difficult adjustment for a hitter to make after facing Moore two or three times earlier in the game. Additionally, each pitcher has thrown the slider as their second most frequently used pitch. Again, Altavilla’s slider is significantly faster and has more horizontal movement, adding another adjustment for hitters to make.

As the game progresses, a solid candidate to replace Altavilla is Nick Vincent. They are close in height, and have nearly identical release points.

Batters will be seeing a similar repertoire from the same arm slot at vastly different speeds with different movement. If Moore, Altavilla, and Vincent can’t combine for eight innings, pairing Vincent with any of the other fastball-slider pitchers, like Zych, should bridge the gap and allow Diaz to take over in the ninth.

Pairing a bullpen arm with Ariel Miranda is no easy task. There are only two lefties in the ‘pen, one of which is a LOOGY, and no one really replicates his pitch arsenal. Fortunately, Miranda has been able pitch deeper into ball games than other pitchers in the rotation, averaging six and a third innings per start in his last eight appearances.

Perhaps the most ideal replacement would be James Pazos. Their identical heights lend a similar arm slot, but their pitch styles are very different. One thing I found interesting is the difference in their zone profiles. Miranda pitches to his glove side (inside to righties) regardless of the handedness of the batter, while Pazos tends to throw to the opposite side of the plate more often. These tendencies are magnified with two strikes.

Switching from Miranda to Pazos would force a hitter to adjust to pitches from a similar arm slot in noticeably different locations at different speeds.

Even with Miranda’s ability to pitch deep into games, the Mariners will often need more than Miranda and Pazos to get to the ninth inning. Tony Zych would be an interesting candidate to bridge the gap. The similarities in their fastballs is enticing. If you take the movement on Pazos’ fastball, it’s almost identical to Zych’s, but flipped over the y-axis.

Both fastballs have a ton of run, and both have thrown their fastball over 96 MPH on average for their careers. Zych’s slider has quite a bit more horizontal movement than Pazos’, but adjusting to their mirror-image fastballs should pose enough of a challenge.

The importance of pairing pitchers is to avoid times through the order penalty. Later in games, batters are more likely to succeed against pitchers they have already seen. Obviously, any pitching change helps mitigate the times through the order penalty, but pairing pitchers with subtle differences amplifies this effect. For example, after facing James Paxton twice, a batter is probably ready for a 97 MPH fastball from the left side; however, if you replace Paxton with Pazos it would play to the Mariners advantage. The batter may be prepared for the speed of Pazos’ fastball, but not the different movement. Pazos’ fastball has much more run, without as much “upwards” break. The hitter’s timing may be right, but the change in movement may result in whiffs or weak contact.

Optimal pitcher pairing can help the Mariners avoid the times through the order penalty while helping a pitching staff and bullpen that rank in the lower-third in xFIP hit their stride in the second half of the season. Let’s hope it does.

Go Ms.