Welcome to ‘Uncut Gems’. In this series, I will be reviewing MLB players and prospects who have yet to come into their full, true potential.
In order to identify these hidden gems, data is a must; the traits that pinpoint these athletes' potential can be quantified in the data. Thus, the majority of these player write ups will be very analytics/data heavy -- though I will explain what all of the data means and how it’s applied.
The Player
The player going under the microscope today is Miami Marlins reliever, Adam Conley. Conley was drafted 72nd overall by the Marlins in the 2011 draft. With his elite velocity and unique low three-quarter arm slot, he was thought to be an arm with a very high ceiling. Conley debuted for the Marlins in 2015 as a relief prospect, where he posted a solid xERA (expected ERA) for a reliever of 3.57, and a barrel percentage of 5.1%. Conley’s fastball sat around 95, touching the upper 90s, suggesting that he could shape up to be an elite bullpen arm.
However, this was not to be. By 2017, Conley’s ERA had ballooned to nearly double that of his rookie season (6.14), and his struggles were validated by his xERA (5.76), xwOBA (.367), xSLG (.498), and a barrel percentage of 8.2%. In other words, Conley’s poor on field results were backed up by the probability models.
In 2018, Conley had a bit of a rebound, lowering the barrel percentage to 4.5% (career best), raising his strikeout rate to 24.8% (also career best), and reducing his xERA to 3.98. The hard hit percentage of 36.8% was still concerning (around the same numbers as regression years), but it looked like he was figuring it out going into 2019. Sadly, he did not. In 2019, Conley’s weighted OBA was the worst of his career (.375), his average launch angle went up over five degrees, and his ERA and xERA skyrocketed to 6.53 and 5.29 respectively (both career worsts).
So what went wrong with Conley? A guy with a unique armslot and upper 90s fastball from the left side should not struggle the way he has (32nd percentile in whiff rate, 15th percentile in expected batting average, etc). The potential is there, and at 30 he still has plenty of time to make the necessary adjustments to become a top of the line reliever. So how do we get him there? Step one is to look at The Arsenal.
The Arsenal
Conley’s arsenal consists of four pitches: a four seam fastball, a changeup, a curveball, and a slider. The four seam fastball generally lives in the mid to upper 90s, topping out at around 97-98 mph with a spin rate of 2329 rpm on average, coming from about a 10:00 axis. In terms of movement profile, Conley’s heater showcased roughly 16.4 inches of vertical break, extremely unique for someone with a low three-quarter arm slot. As expected with his slot, the offering also showcases a solid amount of armside run (13.6 inches).
His changeup is the secondary pitch he utilizes most, with the offering averaging 86.5 mph with a mean spin rate of 2033. The changeup showcases a plus 16.3 inches of horizontal run, while dropping 27.7 inches (gravity included). This fading change is his best secondary offering.
The two breaking pitches (slider and curveball) are very similar in profile, and could almost be blended together. Both share a lot of gyro action, as observed by their similarly low efficiency ratings (18.2% on slider, 33.9% efficiency on curveball). The two also share similar movement profiles, with the slider breaking two inches to the glove side, and the curve breaking just over four inches. The two pitches also have relatively similar vertical break characteristics (for a slider and curveball), with the gravity included drop being within ten inches of each other. The goal of a slider is to kill vertical break via high spin, resulting in a low vertical movement offering with glove side run; the curveball’s goal is to induce vertical break. The spin rates on the slider and curveball sit at 2112 and 2208 rpm, with the pitches averaging 86 and 83 mph respectively.
In regards to his pitch location, Conley tends to throw the fastball in all parts of the zone, mainly attacking the middle and upper thirds (pitch height avg of 2.73 feet). On the changeup, Conley typically attacks on the arm side (i.e. outer third for right handers), typically locating low in the zone to induce ground balls. With his two breaking pitches, the location profiles are nearly identical (mostly low and in on righties, low and away on lefties) as expected due to their similar movement characteristics.
Conley’s pitch arsenal and locations for the 2019 season
Pros
Build/Frame: Conley’s athletic 6’3’’ 209 frame screams perfect pitcher build. The lankiness allows for maximum leverage, while giving him the potential to extend really well due to his long legs and plus flexibility. In theory, Conley could develop elite extension, looking very much like a Chris Sale in regards to extension and release characteristics.
Armslot: Conley’s unique low three-quarter slot is a perfect compliment to his lanky build. The armslot is not only an unconventional look that can surprise hitters, but it allows for a lower vertical approach angle. This is ideal, as low vertical approach angle fastballs at high spin and velocity (what he has) play brilliantly up in the zone (exactly where a high velo fastball would be best located). Additionally, the low armslot carves Conley a niche out of the pen as a guy that could get lefties out especially well. His release x (how wide in relation to the plate he releases the ball) is 3.39 feet and it comes from behind the head of a left handed hitter.
Fastball Profile: Conley’s fastball profile is quite frankly fantastic due to multiple factors. First off, Conley possesses plus velocity, which touches the upper 90s. This is hard to find in left-handed bullpen arms, especially those with a very wide armslot. Moreover, in the last couple of years, Conley has shifted the tilt of the pitch more vertically, which has given it more vertical break. This is important because pitchers with wide release points typically emphasize horizontal run. In particular, the more vertical axis allows for both types of movement on the pitch (16 inches+ vertical break, 13.5 inches horizontal break in 2019). Conley’s fastball efficiency currently sits at 90.4%, which is solid in general. However, it is worth noting that in 2018 (his best season), he had an additional 1.6 inches of vertical break and 0.6 inches of horizontal break, suggesting that he has been even more efficient in the past; he has room to gain that extra break back with added efficiency.
Despite having a very high release and short extension, the combination of Conley’s velocity and unique tilt on the fastball still make it a threat.
Plus Changeup: The fact that Conley has a plus playing changeup is massive for the future of his potential arsenal. Typically when looking at relievers, it is common that most guys with two solid pitches have a plus fastball and breaking ball. While Conley’s breaking pitches are not very good, the fact that he has a changeup that fades with 16.3 inches of horizontal run (18.9 inches in 2015) tells me that once a breaking pitch is developed, he could have a higher ceiling as he would have an additional plus offspeed pitch. His changeup is particularly effective against right handers, which is important as it gives him viability against hitters from both sides of the plate.
Cons
Bad Extension and Relative High Release Height: When evaluating a pitcher, one of the first things a scout looks at (data wise) after the build of the player is both his release height and extension. Given the characteristics of his pitches (high velocity, rpm fastball with low three-quarter arm slot), the assumption would be that Conley should have a big extension, resulting in a very low release height (and elite vertical approach angle). However, Conley’s release height is nearly six feet (5.92 feet on fastball and breaking balls, 5.95 on changeup).
This is completely opposite of what should be expected of someone with his armslot and pitch profile, and it is completely counterproductive to his success. His release height is so high because he has such a terrible stride/extension. Conley’s extension is a pedestrian 6.14 feet, almost three inches less than his height. Player height is considered the minimum adequate extension to create a good vertical approach angle. In essence, Conley’s stride is so short that it completely counteracts his unique armslot, rendering its potential advantages null and void.
In contrast, Josh Hader (same height/build as Conley with similar fastball velocity and spin rates) releases the ball at 5.21 feet (ideal vertical approach angle). The reason for this? Hader has an extension of 6.88 feet. Considering Conley and Hader have essentially the same build, there is no reason for Conley to have such a short extension. He will need to fix it in order to reach his potential and succeed at the big league level; if he doesn't, his pitches will continue to come in very average and he will get hit hard (the way he has thus far in his career).
As seen on this breaking ball, Conley is standing extremely tall at release. The short stride and overall lack of knee bend/gute sink essentially eliminates the potential approach angle advantage that his armslot would normally create.
Poor Breaking Ball Characteristics/Lack of Pitch With Solid Glove Side Break: As mentioned when discussing Conley’s arsenal, his curveball and slider have pretty much the exact same characteristics: high gyro, low spin, average velocity, with so-so vertical and minimal horizontal break. While high gyro is something that you want out of a slider, the low spin rate completely counteracts the gyro spin’s usefulness.
When it comes to breaking pitches, the higher the spin rate, the more spin induced movement. With Conley’s slider spin averaging 2112 rpm, it’s frankly poor. The lack of spin makes it so the pitch essentially just sits up there at a slower velocity (two inches of horizontal break), with the gyro spin preventing maximum vertical break (which should be present on a curveball).
While the goal of a slider is to not have a ton of vertical break (hence gyro spin), his curveball’s efficiency is just 33.9%. This means it too has a lot of gyro spin, killing its ability to have elite vertical break (the goal of a curveball).
Essentially, Conley has two breaking balls that don't spin enough to create the desired break profile; even worse, the gyro on the curveball is totally counter productive to maximizing the vertical break on that pitch. These offerings are both a lost cause: he has to find another option with armside run for him to even be an average MLB reliever.
How to Fix this ‘Uncut Gem’
Mechanics: As mentioned prior, Conley’s build, fastball profile, and armslot all scream low vertical approach angle. Yet, his poor extension is preventing him from creating said angle. In order to fix Conley, the first step is to extend his stride and release point closer to the plate. His current extension will probably need eight to nine inches added to it in order to create the desired effect, though a smaller five to six inch gain is very obtainable, and would give him a release height that resembles the desired profile.
Conley stays very tall after his leg kick, which prevents him from sinking into his glutes and driving off the mound. An adjustment that could be made would be to have him sink into his back leg after the leg kick, which would result in a deeper, lengthier push off of the mound (creating the desired extension) instead of the immediate front foot collapse and plant that he has today. Conley is also very tall after planting, and could sink into his glutes much more post front foot land.
If Conley were to sink in pre-drive and then sit into his glutes post plant, he could flirt with a sub five-foot release height, creating a desired elite vertical approach angle.
This is the farthest down Conley sinks. Instead of driving forwards downhill (sinking into his glutes), Conley pops back up, straightening out his back leg and as his front leg immediately collapses and lands prior to there being any sort of drive downhill- he is as tall as he possibly can be.
Arsenal: With a unique playing, high velocity fastball and a plus changeup, Conley is missing one critically important type of break from his arsenal- something to the glove side. With the slider and curveball being pretty much useless, I believe the best call for him would be to scrap the two completely. Instead, a cutter could be the solution to this problem. With a fastball touching 97-98, he should be able to throw a cutter that hovers around 90-92, which would be more than enough in the velocity department. Conley can get the desired horizontal break by improving the spin efficiency on his slider, turning it into a cutter.
The fact that he throws a fastball with above average spin suggests that he could get tight enough rotation on a cutter for it to get the desired horizontal break profile. If he could make these adjustments, he would have offspeed pitches that break to both the glove and armsides, making his viability as a plus bullpen arm legitimate.
Projection
As mentioned at the beginning of this piece, Adam Conley has the physical profile and fastball characteristics to be an elite relief pitcher. The low and wide armslot suggests that he could be dominant against left handed hitters, and with plus velocity and spin could be a real strikeout threat. However, Conley’s lack of a pitch with glove side break, and his abysmal extension have created a situation where Conley is lacking an out pitch to left handers (who he has struggled against). Additionally, his unique armslot can't create the desired vertical approach angle that should come from the aforementioned low arm slot.
If Conley were to make the adjustments listed above in the “how to fix” section, I could see him becoming a top notch reliever. With pitches that break in both horizontal directions, and a fastball that could play elite, there is no reason why he can't be a dangerous arm if the optimal approach angles are created. Only time will tell what comes of Conley, but at thirty years old he still has time and the potential is clearly there.