Lucas Giolito was once the 2012 draft’s odds-on first-overall selection. As he began his senior season at Harvard-Westlake, Giolito was seen as the most talented player in a draft class that included Byron Buxton and Carlos Correa. It would have made him the first and only high-school righty to be selected at 1.1 in the draft’s history. But then Giolito felt discomfort in his elbow during the first inning of an early-March start (he was up to 100 mph and had thrown a one-hitter the start before) and removed himself from the game in the second.

An MRI revealed damage to Giolito’s UCL but not so much that he would require immediate ligament reconstruction. Despite that, Giolito’s season was over and so, too, were his chances of going first overall. As the draft approached and the Astros, who possessed the first pick, shifted their focus toward Correa and other prospects (including Giolito’s teammate Max Fried), the industry wondered when and where Giolito would be selected. There wasn’t much precedent at the time for pre-draft UCL injuries and Giolito’s stock remained volatile until very late in the process. He was still being mocked within the top-five picks into late May.

The Nationals drafted Giolito 16th overall and signed him, at the deadline, for $2.925 million, exactly $800,000 over the pick’s slot value at that time and about $300,000 more than the slot’s value in 2016. Giolito threw two innings for the Nationals’ GCL team on August 14th of that year. On August 31st, Dr. Lewis Yocum fixed his elbow.

Giolito returned 10 months later, especially notable considering that effective Tommy John rehabilitations generally require 12-18 months. It has been almost exactly three years since Giolito made his first post-TJ start and his stuff has returned to pre-surgery levels.

This season the fastball has mostly been 93-96 and up to 99 (even from the stretch) with a rare combination of downhill plane and horizontal movement. That plane comes from Giolito’s size (6-foot-6, 255 pounds) and trebuchet overhand delivery and leads to plenty of ground balls. According to MLBfarm.com, 54% of balls put in play against Giolito have been grounders. While his fastball merely flashes 80 velocity and usually sits in the 60-70 graded range, it plays up because of the downhill plane and because of moderate deception in Giolito’s delivery.

Giolito has had some issues with control this season, including his last start for Double-A Harrisburg in which he walked four in 4.2 innings. Things unraveled in the fifth inning of that start – he recorded the first four outs of the game on five pitches – as Giolito walked three hitters in that frame. Command issues aren’t unusual for massive 21-year-olds; that Giolito has only had rashes of it for the odd start or inning is more encouraging than if it were a chronic issue plaguing him every time out. Giolito had not walked multiple hitters in a single June start until his last outing. While we may see some strike-throwing issues early in his MLB career, I think Giolito will eventually have above-average control and average command.

One evaluator who has seen Giolito struggle with control think he gets preoccupied with runners on base. Pitchers of Giolito’s size often have long times to home from the stretch – Giolito hovers around 1.5 seconds, which is a little slow – and have to do more to vary their pacing to disrupt would-be base-stealers. Giolito has improved his ability to hold runners but it isn’t yet second nature to him, and it’s possible some of his strike-throwing issues stem from this particular aspect of his growth. That said, he shows no notable uptick in his walk rate with runners on base.

The secondary stuff, especially the curveball, is impressive. Giolito’s fabled curveball has an incredible amount of depth to it considering its velocity. It comes in around 82-84 mph but still features great downward movement and will sometimes bend horizontally as well, especially when it’s located to Giolito’s glove side. He has become particularly adept at locating the breaking ball to the back foot of left-handed hitters and he can throw it for strikes in the zone as well, though he does this less often. It’s an easy plus pitch that flashes plus-plus.

That Giolito has weaponized his breaking ball against lefties is especially important considering that his changeup, which spans about 82-86 mph, is clearly his third-best pitch. The quality of the cambio ranges anywhere from a 45 to a 55 on the scouting scale and projects to sit at the top end of that range as he matures. When Giolito maintains his arm speed and locates the pitch down and to his arm side, it looks like the fastball out of his hands and slips down and away from left-handed hitters.

This is the best pitching prospect in baseball. Elite size, velocity and a potentially elite curveball with the requisite athleticism both to throw strikes and develop a, not only acceptable, but potentially impactful changeup. Giolito is the rare minor-league pitcher who, based purely on grading out stuff, has top-of-the rotation upside. I think, initially, he’ll allow more contact (especially on the curveball) than most are anticipating and there will inevitably be other growing pains. But barring something catastrophic, I believe Lucas Giolito will eventually become a #1-2 starter, the bane of the existence of hitters every fifth day for many years.