Raising Aces: Debut Ante: Jon Gray

The heat that put him on the map was present and accounted for in his debut, with a fastball that averaged 95.2 mph and touched 97.5 mph, according to Brooks Baseball. He threw the heater on 52 of his 77 pitches (67.5 percent), dominating his repertoire, and his best fastballs featured an extra dose of movement. He added 17 sliders and eight change-ups, though his command of the secondary arsenal was shaky. Gray missed arm-side with a lot of fastballs while nearly all of his sliders ended up outside the strike zone to the glove side. I was disappointed at the relative down-sizing of his changeup usage, and though it could have been a single-game blip on the radar, his impressive development of the pitch–from afterthought to effective weapon in the minors–will hopefully continue as he gains confidence in his off-speed stuff.

His ability to make adjustments and improve some of the essential elements of pitching, including stuff and mechanics, are responsible for a good chunk of the optimism that I hold for his future. The defense behind Gray didn't do him many favors in his first start, giving away extra bases with fielding mistakes and unforced errors, and one of the three runs that he allowed was of the unearned variety.

Mechanics Report Card

Gray received excellent grades in the 2015 Starting Pitcher Guide, scaling to a B+ grade that was the top GPA among prospect pitchers. Those grades had a peak flavor to them, with a nod to the better performances that I saw last year, but the above grades have taken a step backwards. What was 65-grade balance is down to 60, a mark that is still plus but has gone backward since last season, as Gray has a little bit more of a drop to his delivery and will get some side-to-side wobble on some pitches.

One can excuse Gray if his he was pumping adrenaline in his debut, as it's common to see pitchers who find another gear when pitching in MLB for the first time, and the physical rush can simultaneously add velocity and subtract pitch command. He finishes with plus posture, on average, though Gray will veer between 55- and 65-grade spine-tilt from pitch to pitch.

His 70-grade torque remained intact, thanks to a blend of early hip rotation, a generous upper-body load, and a delayed trigger that helps to increase hip-shoulder separation. His hips rotate into an open stride, with his front foot landing to the first-base side, and the extra degrees of hip rotation needed to open up the hips effectively upgrades his torque. His momentum, which used to be plus, has taken a step backward when comparing last Tuesday's start to earlier in his career. He has fixed one major ailment–when drafted, Gray had a tendency to lock out the front knee after foot strike, similar to Justin Verlander, but Gray has since ironed out the delivery by adding flex in the front knee that allows him to track forward from foot strike through release.

Gray still flashed a solid burst but his stride-speed was shaky, and though his forward movement still had a good direction and initiation of momentum, many of his deliveries lacked oomph. Momentum was an aspect that he had improved last season, so perhaps he is just falling back into old habits. If the slower move worked to increase his ability to repeat his mechanics then I would be all for it, but like with most pitchers, Gray has had a tougher time repeating the timing elements of his delivery with the slowed pace to the plate, and his below-average grade for repetition underscores the issue.

All things considered, Gray's balance was still excellent, his torque still awesome, and though he struggled to line up the gears he did flash the B+ delivery on occasion. I'll grant him the same caveats that come with an MLB debut, with the expectations of increased power, decreased stability, and a tougher time repeating the delivery when compared to a typical start. The key is to watch the next few starts in order to understand which traits may have been an artifact of his debut and which skills will be more persistent over time. He has all of the physical and mechanical underpinnings of a successful pitcher, and though his home park might obscure his talent in the mirage of a pinball atmosphere, the pitcher that I saw in his debut was not as far off of his prospect track as some reports had indicated, and I am anxious to see how his game translates to sea level over a longer stretch of pitches. We'll find out what that looks like today as Gray takes on the Mets in Flushing.