This week's trip through the bushes takes us to the Colorado system to evaluate the top prospect in the Rockies’ pipeline: Jonathan Gray. The 6'4”, 255-pound right-hander has an elite arsenal, with an intimidating fastball complemented by a plus slider and a changeup that is considered a major asset. That repertoire should play very well in the majors and would seem to be a strong fit for the thin air of Coors Field. Gray's profile is even more intriguing once we get past pitch selection, so let's dig into the specifics that make him such a unique specimen.

Gray was picked by the Rockies with the no. 3 overall selection in last year's draft. A product of University of Oklahoma, he was the second pitcher off the board, following top overall selection Mark Appel. Gray is widely considered to possess the higher ceiling and the lower floor, and the early returns sugget that he’s raising the floor quickly. In fact, I’ve been so impressed by Gray’s rapid development that I ranked Gray as the no. 1 pitching prospect in baseball when Paul Sporer and I broke down the list in the latest episode of TINSTAAPP. (He’s the eighth pitcher listed on the Top 101.)





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Gray's college stats were predictably ridiculous: 147 strikeouts against 24 walks in 126.3 innings pitched, with a 1.64 ERA. He allowed just 83 hits and a lone home run in his last college season, and he didn't let any baseballs leave the yard in the pros, underscoring his dominance and potential to succeed at altitude. Gray got his feet wet with short stints in rookie ball, and his pro statistics blossomed after he was tossed into the dreaded California League, with a K-to-walk ratio of 36-to-6 and just 10 hits allowed as he stretched his wings for five innings per start.

Gray has an elite fastball that earned an “8” grade from the Jason Parks and the BP Prospect Staff. The pitch was absolutely overpowering in the minors, producing late swings with high-90s velocity that occasionally broke triple digits. Gray did go through periods in which he would consistently miss high with the heat, but he balanced things out with stretches in which he painted the lower shelf of the strike zone with the fastball, showing off tremendous downhill plane. He tended to fall in love with the heater when behind in the count, however, though he rarely found himself in that situation.

Opposing batters were clearly geared up for the pitch, sitting on heat early in the count (especially in his pro debut on July 10th), but Gray was able to make adjustments and showcase his filthy array of secondary pitches.

Gray’s breaking pitch is a tight slider that is thrown at high velocity and features late break, serving as another power pitch that plays extremely well off the fastball. The prospect crew tabbed Gray's breaker as the top slider in the minors, with two-plane movement that includes a steep vertical component at times. Hitters were visibly uncomfortable at the plate against Gray, with ugly hacks that resulted from their attempts to discern fastball from slider. He was a bit fastball-heavy in his debut, but as the season wore on, Gray got more comfortable with throwing sliders in early in the game and early in the count.

The changeup was the largest point of emphasis for Gray in his first taste of pro ball, with the Rockies adhering to a developmental plan that mandated his increased use of the pitch. Gray admitted that the pitch was “a little rusty,” as he had hardly needed it in college, instead relying on his filthy fastball-slider combination. His learning curve with the pitch was astonishing: In his pro debut there were a handful of changeups that badly missed their targets, some of which even involved alterations to his delivery (i.e. slower pace or slower arm), but within a month he was using the change as a weapon to take advantage of over-zealous batters who were parked in the hot zone and waiting for the hard stuff.

Gray featured an impressive velocity differential and great fade on the pitch, and though he still uncorked a few duds, the changeup’s overall quality noticeably improved in just a few short weeks of rookie ball. By his final start for Grand Junction, Gray was punching out hitters left and right with two-strike changeups, flashing the type of learning curve that augurs a future ace. The prospect crew gave his change a potential 6+ on the grading scale, likely taking his rapid development of the pitch into account.

I was extremely impressed by Gray’s rapid in-season development, as the pitch became more effective with each passing game, and he quickly adapted to the pitch in terms of sequencing. His season served as an excellent example of why teams choose to limit the use of certain pitches for their young arms, opting to emphasize fastball command or the development of additional secondaries with an eye toward privileging big-league performance over minor-league stats. This adds an exclamation point to the caveats associated with minor-league numbers, especially for pitchers, and it boosts the optimism that Gray could be a beast when his full arsenal is unleashed at the highest level.

Mechanics Report Card









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For an explanation of the grading system for pitching mechanics, please consult this pair of articles.

At peak, Gray receives above-average grades in every category, but there was a clear progression of mechanical efficiency from his debut to the point where he achieved that peak. Gray took some flack in college for his stiff landing leg, which straightened after foot strike and through release point. The stiff landing leg wasn't a major red flag (Justin Verlander has been just fine with it), but it did limit Gray's ability to extend his release point by tracking the body closer to the plate after foot strike, a strategy that requires flex in the front knee. Sure enough, Gray began to address that minor issue, and his front-knee flex got better over his six weeks of minor-league pitching.

More importantly, Gray was able to refine the balance component of his delivery during his short stint in pro ball. In his first start, Gray had a more pronounced drop in his center-of-balance after max leg lift, with a back-leg collapse that created a tendency for the head to lag behind the body. It may have been a case of nerves, or perhaps the after-effects of not having pitched competitively for a month, because Gray was able to stabilize his motion over the next few weeks. His balance was most impressive from the stretch, with a much-minimized drop and excellent lateral stability despite the fact that he maintained a substantial leg lift with runners on base. The peak result was the 65 grade that is reflected in the report card, and he has the upshot for future 70 grades or better in the category if he continues to diminish the drop in his delivery.

The stability issues from Gray’s first two games had a ripple effect on his repetition of mechanical timing, but his consistency improved along with his balance over his short season. He possesses a unique combination of elite torque and excellent posture, demonstrating a blend of power and stability that is rarely seen among young pitchers. The massive torque involves a healthy combination of upper-body load and a delayed trigger after foot strike, allowing his hips and shoulders to play near-equal roles in his generation of separation to induce killer arm-speed. Gray finishes with minimal spine-tilt and a head position that stays above his center-of-mass, and he could have an 80 grade for posture in his future if he continues to gain functional strength and flexibility.

I gave the overall package a B+ grade, which ties with Jameson Taillon and Kyle Zimmer for the highest mark among this year's class of pitching prospects. Gray has the highest mechanical ceiling of the bunch, with the upshot for elite grades in multiple categories and the stability to lead to better repetition down the road, all wrapped in a powerful frame that adds to his intimidation factor on the mound. The most impressive part of Gray’s profile has been his incredible ability to make adjustments to his stuff as well as his mechanics within a very narrow time frame, and to do so without making sacrifices to his signature delivery. He has the potential to earn the extraordinary straight-A GPA, and his Doogie Howser learning curve increases the odds of reaching that ceiling.

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Thanks! Jon Gray was my top pick in my dynasty draft this year (3rd overall, after Bryant and Abreu), and I appreciate the deeper look into what makes him such a premier prospect.
Great stuff Mike,
Gray seems to be a very impressive young pitcher. Although I am not high on comps , mechanically does he remind you of anyone past or present ?
/watches slider GIF for 15 minutes
Nice write up - its encouraging to see a highly touted pitcher in the Rockies system actually improving!

And before you get attacked by an angry Sooner fan, Gray played at OU, not OSU.
That slider made it move. Bananas.

Also, the final gif. Is this a practice session? I see no fielders behind him, it totally threw me off.
His delivery will have him undergoing Tommy John surgery with in 2 yrs.