In the era of the “MVP Machine” and the capacity for players to construct more valuable versions of themselves utilizing data and cutting edge training, continual evaluation of young players is a requirement. Profile evolution is a constant, as contradictory as it seems, and it is most often seen in young pitchers.
Zach Plesac has been a pleasant surprise during a season of dire injuries or illnesses to starting pitchers Corey Kluber, Carlos Carrasco, and Mike Clevinger. Five starts and a 2.52 ERA is certainly positive, though FIP and xFIP both have Plesac in the high four range, a more concerning proposition.
In summarizing his concerns about Plesac’s limitation on June 6, 2019, WFNY’s Mitchell Krall astutely noted:
Zach Plesac, on the other hand, really only has the fastball and the change-up. Unfortunately, there just aren’t many successful major league starting pitchers who rely on two non-knuckleball pitches.
Since’s Krall’s post, Plesac has been mostly the same in terms of usage.
Plesac has an interesting arsenal, a plus changeup with good command, a heavy fastball, and a slider which is inducing Plesac’s most whiffs against right handed hitters; a potent 33% against righties.
However, the curveball simply has not been effective against RHH so far, partially because of location, and partially because it is in the 6th percentile in spin rate of big league curveballs. At the moment, the curveball just is not good enough. The slider? Well it may be. At 27% against RHH it has been a very good pitch but one which gets significantly less break than the average slider.
However, a portion of the value of the slider may be that his fastball gets above average movement and slider below, playing well off each other.
In many ways, slider looks like the only third pitch that may flash average above for Plesac but he refuses to throw it to lefties, and leans on fastball change with a little curveball. Ultimately, it would be nice to see Plesac add 5% usage to his slider against lefties, reduce the fastball use.
Yet, one fascinating part of Plesac’s unsustainable BABIP against of .192 and unsustainably high HR/FB% against of 16% is that Plesac may have real contact management skills.
Yet, Hard Hit% can be deceiving. Plesac is allowing a barrel rate against of 13.1%! For context, Mike Trout has a barrel rate of just 12.9%. Which means Plesac is giving up a barrel rate which would reflect facing roughly 9 Mike Trout’s a night.
Likely, a portion of this is noise but also, there is regression coming; hard and fast.
When a pitcher is a high use fastball pitcher, he cannot spend his time in the middle of the zone; so far Plesac has done it with frequency.
Plesac’s results have been exemplary so far but if his usage and approach continue, the results will crater. At the moment, Plesac appears to have control but not command. That is, Plesac throws a lot of strikes but not a lot of quality strikes, rather a lot of hittable strikes.
While the broader question for Plesac is whether he can throw an effective third pitch, which will likely be the slider, the central question is whether Plesac can begin to command the fastball well enough to more effectively set up secondary pitches and manage contact.
At the moment, Plesac’s fastball flashes nothing but promise. Yet, without a significant improvement in command, Plesac looks more like a high leverage reliever than a starter.