Fernando Romero and Designing A Slider From Hell
Image courtesy of Brad Rempel-USA TODAY SportsThe Twins acknowledged that Romero is currently a two-pitch pitcher. Technically, he has three types of fastballs (but two movement patterns), a promising slider, and a developing change-up but, functionally, he has a fastball and a slider. Because of this, the front office believes he is better served coming out of the bullpen (or at least in a role that limits his times through the order).
Foundationally, Romero’s fastballs are solid for any pitching role. The mid-90s-plus 4-seam fastball can be elevated while his 2-seam and 1-seam fastballs burrow down-and-in to right-handed hitters. From a pitch sequencing standpoint, this is something to build upon.
In the most basic sense, depending on the shape of a pitcher’s breaking pitch, when you have an elevated fastball, it would be best to have a curveball that can tunnel with it before descending out of the path. Likewise, if you have a running sinker, you would like to pair it more with a slider running the other direction, similar to how Kyle Gibson tunnels his. Ideally, a pitcher would have a variety of pitches moving in different directions to keep hitters defending the entire zone but a pair of complementary pitches can carve opponents up. After all, Glen Perkins had an impressive run as the Twins’ closer with a two-pitch repertoire.
So what is the shape of Romero’s slider? The greasy techie data says that it is one that has 8.2 inches of break length from release to the plate, which is average from a right-handed pitcher, and a below average break angle of -2.9. The break angle essentially means which direction and how much the pitch is running. A break angle of 0 means the pitch follows a straight path from the release point to the target with no movement in any direction. If the break angle is positive, it means it is moving toward a right-handed hitter. Negative, toward a lefty. Romero’s -2.9 break angle means it has some movement toward left-handed hitters while the average right-hander’s slider has a break angle of -8.1.
(To give a better picture of what break angle means, you can compare Fernando Romero’s -2.9 break angle slider with the new Yankee Adam Ottavino’s frisbee slider with a -21.5 break angle slider who is on the opposite end of the slider movement spectrum.)
So that is the essence of his best secondary pitch. It’s thrown fairly hard (the average slider is thrown at 84 mph and his clocks in at 87), moves slightly away from right-handed hitters, and has about league-average break.
Before coming to the big club, Paul Molitor described Romero’s slider as “inconsistent”, which is exactly how it played for the Twins. On occasion, Romero would spin a nasty hoochie woochie but on others, it would back up and sit on a platter for a lucky batter.
While Romero’s 36 percent miss rate on the slider is above average (and actually higher than that of the oft-celebrated Ottavino), opponents posted a .723 OPS and an 88 mph exit velocity (higher than the MLB slider average of 85.8 mph) off of it. It is a small sampling, to be sure, but one can look at these numbers as an affirmation of what Molitor suggested.
One reason for the middling production was simply location. If you divided the zone in half across the middle, separating upper and lower quadrants, his slider landed in the upper quadrant 40.1 percent of the time (significantly higher than the 25 percent league average). The good news is that hitters did not completely decimate sliders left up - but they didn’t swing through them either (just a 5% swinging strike rate up compared to a 25% one when he kept it down).
The location cost him some strikeouts, leaving the ball spinning up in two-strike counts where an otherwise well-executed slider would have been a kill shot.
In terms of sequencing, Romero’s slider has actually played well off of the 4-seam fastball, enticing a miss rate of 40 percent and a 39 percent chase rate out of the zone in a fastball-slider pairing. On the other hand, opponents may be able to tell the difference between his slider and sinker as they have a 33 percent miss rate and just a 15 percent chase rate on his slider after being set up by his sinker. If Romero does nothing to tweak his slider heading into the 2019 season, at the very least he should be pairing it more frequently off his fastball.
Here is where the new-look, data savvy, tech-reliant Twins organization might be able to optimize Fernando Romero’s stuff.
It would seem that Romero is a prime candidate to receive the pitch design treatment — a retooling of his pitches guided by Rapsodo technology and high-speed Edgertronic cameras. Championed by Driveline Baseball, the baseball training company has found some best practices that can identify issues and improve a pitch’s performance based on certain modifications. Before pitch design technology became available, the previous best method to improve this was to have a pitching coach observe bullpens, giving the pitcher cues and provide affirmation when the ball seems to react differently. Then they hope that a player carries whatever feel they had during the pen into the game. Between the diagnostic process and communicating what the problem and solution might be, there could be a long trial-and-error period. Now, however, armed with the new tools, a pitcher and the player development team can isolate the issue, diagnose it and set forth a plan to correct it.
The first issue for Romero is consistency, which seems to track back to the moment the pitch leaves his hand. When he releases the slider, it may be that he is letting go too early or with different hand tilts. As researchers at Driveline have demonstrated, even the smallest minutiae such as fingertip contact points can wildly change the spin and flight path.
Admittedly, without the high-speed cameras, it is difficult to properly diagnose the issue but from the limited slow-motion release clips, we can see where Romero’s slider needs work. Here is an example of how the slider comes out of Romero’s hand.
Romero’s thumb is tucked and his fingers are wrapped around the bottom of the baseball. At this juncture, the thumb is making very minimal contact while his index and middle fingertips are applying pressure. Then he snaps across. On average, he imparts 2,431 rpm worth of spin on his slider, which is about the league average spin rate for right-handed sliders (2,413).
Now compare that to Justin Verlander’s slider grip and release (image courtesy of Pitching Ninja) -- the one that Verlander reportedly improved upon while using the Astros’ bevy of Edgertronic cameras to isolate his release point.
Notice how his fingers wrap the side with more contact points on his fingers. His release motion also comes down diagonally through the ball. The results were two more inches of run than Romero’s slider as well as 200 more rpms of spin (2,684 average). The added rpms is important because each increase of 100 or more translates into more swing and misses.
Of course, not everyone has the same release or arm path. Verlander’s 6-5 frame and over-the-top delivery might preclude Romero from copying his style. Romero’s slider release almost mimics that of Marcus Stroman, whose pitch was the basis for Trevor Bauer’s recent slider rebuild (which is now superb). This may be a template for Romero to unleash hell on an improved pitch.
Like Verlander’s, Stroman’s slider grip is held deeper in the hand, which can account for more spin. Stroman’s release has his hand placement similar to Romero’s (underneath rather than like Verlander’s wrapping the side) but unlike Romero’s, Stroman has more contact with the baseball, most noticeably with his thumb (Stroman’s is flush whereas Romero’s makes contact on the side of his). The action differs slightly too as Romero pulls across while Stroman’s hand pulls down.
To be fair, Romero’s slider numbers actually outperformed Stroman’s in 2018, with a higher swinging strike percentage, but Stroman’s numbers took a step back on the pitch this last season where he had previously had a swinging strike rate of 21 percent and a chase rate of 41 percent (with 17 and 33 being league average on the pitch). That said, Stroman’s metrics exceed those of Romero, with a 12-inch break and a 2,654 rpm spin rate. If Romero can emulate this pitch consistently, it will give him a significantly improved weapon and be a cornerstone swing-and-miss pitch vital for late innings relief.
At the very least, tweaking his slider to give it more consistent depth and tilt could help create a monster in the bullpen. What’s more, if he reinvents his slider and maintains the more cutter-ish version, he might have the necessary three-pitch mix to be a force in the rotation.
The Twins have built a player development infrastructure -- both the best tech and the best minds — to address this very issue. Now we will get to see it in action.
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