Welcome back to our series on the innovations the Yankees pitching department is making with the sinker! They've dusted off the pitch from a period of league-wide dormancy and have a renewed focus on disseminating it across as much of their pitching room as are willing to use it. In May, I kicked off the series by looking at the way Cam Schlittler has incorporated the sinker into his arsenal and how that decision helped launch him to the stratospheric heights he is now pitching at. Then in June, I wondered whether the sinker was the solution to Ryan Weathers' home run woes , something my colleague Andrés revealed to indeed be the case just last week.
Next up on the docket, we turn our attention to our first reliever of the series, Paul Blackburn. A converted reliever from his days in the rotation of the Athletics, Blackburn was your classic replacement level mop up multi-inning reliever after signing a big league deal with the team in August of last year. He re-upped on a one-year deal early in the offseason and started his season on much the same trajectory as his previous season ended. Though he owned a far more palatable ERA than his first eight appearances in pinstripes, Blackburn still displayed concerning residuals and underlying metrics that kept him relegated to a low-leverage role.
But then something clicked as the calendar flipped over to June. Since June 1st, among all pitchers with at least 35 innings pitched, do you know where Paul Blackburn's 1.17 ERA ranks? If you said the lowest in MLB, you would be correct. And while a fairly wide delta between that ERA and FIP and SIERA marks in the mid-threes suggests a dose of good luck, an xFIP of 3.32 that is a full run below his career mark prior to that date reinforces that there were material changes to his pitcher profile.
Much of Blackburn's early season struggles can be directly tied to the type of fastball he was using. For the first two months, Blackburn was throwing the cutter as his primary fastball, and he was getting absolutely tattooed. The cutter can be an untouchable weapon when displaying certain physical characteristics and when thrown with precision. The problems for Blackburn's cutter were twofold. First, unlike Mariano Rivera's and Cam Schlitter's cutters, which resemble true cut fastballs, Blackburn's cutter does not exhibit a ton of arm-side movement and certainly does not stay on plane as it travels toward home, and instead much more resembles a hard slider. That brings us to the second issue — a cutter with that shape is not exactly a pitch you want to be throwing in the upper-half of the zone and certainly not one that you can afford to miss centrally.
Unfortunately, that is something that Blackburn was doing with alarming regularity. Blackburn was far too imprecise with his cutter, turning the pitch into a hanging slider when it found those dangerous regions of the zone.
Eleven of the 43 hits he has given up on the season, including four of the eleven extra-base hits, have come against the cutter, and it's easy to see why when you look at how he was deploying it.
Courtesy of Baseball Savant
Then came June and with it a concerted shift in Blackburn's fastball philosophy. Just look at the almost direct correlation between reducing cutter usage and improving ERA (FC% = cutter usage rate):
To replace all those lost cutters, Blackburn turned to the sinker as his primary fastball offering. Of course, that is not all that underpins his rise to bullpen ace for the Yankees. He owes much of that newfound success to the increased confidence he has to throw the changeup and curveball. His cambio grades out as a top-five changeup in baseball at nine Statcast runs better than average while his Uncle Charlie ranks as a top-three curveball in baseball by downward movement vs. average, both pitches inducing whiff and chase rates in excess of 34-percent.
But in my eyes, the sinker has been the key to unlocking the potential of those two put-away secondary pitches. Every wipeout secondary needs to be set up by a reliable fastball you can trust to throw in the zone. Hitters simply are not going to chase and whiff if you cannot establish a presence in the zone with your No. 1.
His sinker is nothing special when it comes to raw characteristics. He throws it at roughly league average velocity — though it is worth noting that he's throwing it two-to-three mph faster than at any point in his career as his relief role allows him to go more max effort — and with roughly league average horizontal and vertical movement.
Instead, the advantages are slightly more subtle. He is able to consistently pepper the bottom of the zone with the pitch, which is the primary factor in his 97th-percentile ground ball rate of 56.7-percent. He also appears to be a master at manipulating the seam orientation to leverage the seam-shifted wake effect we've seen with certain pitches in baseball. His sinker exhibits some of the greatest downward deviation in observed movement vs. the movement profile you would expect from the arm angle he throws it out of. In other words, you would expect his sinker to mainly run in on a righty based on his three-quarters arm slot, but in fact it deviates downwards due to the way the seams interrupt the flow of air across the ball's surface, creating deception for a hitter who is used to observing a sinker breaking a certain way given a certain arm angle.
When you compare the sinker to the cutter, it is easy to see why he made this shift. Blackburn's cutter is allowing a .487 SLG against and is worth zero Statcast runs above average. His sinker is holding batters to a .271 SLG against and is worth five Statcast runs above average. His cutter is pulled 47.1-percent of the time and hit in the air 26.5-percent of the time. Contrast that with the sinker, which sports a much better 28.8-percent pull rate and 18.6-percent fly ball rate. Simply put, it is much harder to do damage against Blackburn's sinker than it is against his cutter.
Blackburn's transformation from bullpen mop-up man alongside Ryan Yarbrough to perhaps Aaron Boone's third-most trusted reliever after David Bednar and Brent Headrick has been astonishing. I'll admit I was ready to jettison him at the start of the season, calling him Boone's personal white flag reliever — when he entered the game, it felt like the Yankees were giving up on the rest of the game. Now, there are few relievers I trust more in high leverage spots than Blackburn, and his reinvention I suspect played a significant role in the Yankees feeling comfortable not adding a reliever at the Trade Deadline.
