Three of the most successful high school lefthanders ever drafted in the first round entered pro ball within the span of 10 years. That trio shares at least one thing in common: All three were physically mature even as teenagers.
Those wins above replacement (WAR) totals, as calculated by Baseball-Reference.com, rank among the seven highest ever for prep lefthanders selected in the first round. (No. denotes overall pick in draft.) The teams drafting C.C. Sabathia, Clayton Kershaw and Madison Bumgarner required no assurances of future physical gains or additional velocity, for they all regularly reached the mid-90s as high school seniors.
North Carolina prep MacKenzie Gore is the top high school southpaw in this year's draft class, but at 6-foot-1 and 185 pounds, he doesn't physically resemble Sabathia, Kershaw or Bumgarner. Then again, not many 18-year-old do.
One can point to just as many success stories for first-round high school lefties of Gore-sized proportions. Not only is that true, but the median height and weight for the 53 high school lefthanders selected in the first round since 1987 is 6-foot-3 and 190 pounds.
In other words, Gore falls more within the bounds of what is typical for a first-round high school lefty than a mature-bodied pitcher like Sabathia, Kershaw or Bumgarner. Fittingly, Gore ranks No. 4 on our pre-draft rankings and could become just the sixth prep lefty to go off the board in the top five overall picks in the modern draft era, since 1987.
The three most successful first-round prep southpaws in that time who were similar to Gore in stature on draft day might offer some hints about his upside.
Cole Hamels and John Danks, in particular, resemble Gore not only in terms of stature but also for their pre-draft scouting reports. Those reports indicate that the hallmarks for all three prep lefties are repeatable mechanics, a fastball that centers on 90-91 mph and feel to spin a plus breaking ball.
Hamels and Danks topped out at 94 mph in high school, but Gore has peaked at 96 this spring, which is encouraging for the development of his velocity as his body matures. Higher peak velocities by teen pitchers generally correlate with higher average velocities down the road.
Additionally, Gore has grown two inches in the past year—he's now closer to 6-foot-2—and might not be done growing. This, too, echoes the case of Hamels, who grew to 6-foot-4 after being listed at 6-foot-2 on draft day.
As it turned out, neither Hamels nor Danks nor Scott Kazmir required elite velocity to succeed in the majors. All three averaged about 91 mph even in their best seasons.
Assuming health and typical physical development, Gore should have no trouble maintaining a 91 mph fastball—and he could sit a tick or two higher at his peak based on his higher velocity readings at age 18.