Pittsburgh Pirates: Top Performing Minor League Hitters Part One

Looking at how the Pittsburgh Pirates prospect hitters in the minor leagues performed in 2018 and who to keep an eye out for in 2019 using z-scores in several offensive categories.

In this month to date, Nick has released our site’s top 30 prospects and earlier in the offseason, I’ve documented composite top 100 rankings based on four major prospect sites.  Today will be the first part of a four-part series, looking at how the Pittsburgh Pirates prospect hitters performed in 2018 to look to see who might be an underrated prospect; the series will go in the order of the really low minors (the three rookie leagues), the low minors (A ball), the upper minors (Double-A and Triple-A), and then ending with a wrap up.

Often times the phrase “you can’t scout the stat line” is thrown around, and it is true, there’s more variables in terms of makeup, a pitcher’s stuff, a hitter’s approach, base running, and fielding, etc.  Teams do try to use a model, with Chris Mitchell’s KATOH being one of the more popular ones, and Kevin Creagh developed the Stat Scout Line.  This analysis isn’t a model, rather a summation of z-scores in different statistics to determine which hitters have performed well compared to other prospects.

Because each level of the minor leagues has different players and the goal is to look at potential prospects (sorry Ryan Lavarnway), setting a maximum age requirement and minimum plate appearance requirement is a must.  Since this is looking at 2018, there will be some players who appear on these lists that are no longer in the organization because of a trade, free agency, or they were released.  For each level among hitters we have the following requirements and the total number of player seasons:

Across each level, the statistics used for how well a prospect has performed will be the following: age, average, on-base, slugging, isolated power (ISO), strikeout rate, and unintentional walk rate.  Strikeout rate will be multiplied by negative one as a lower than average rate is better, and the same goes for age; a prospect younger than average and performing deserves more credit.  The averages for each level are:

Rookie: Gulf Coast League (GCL)

The GCL features a lot of raw players, most recent high school draft picks and first-time stateside players.  There are some players that do stick out for the Pirates, especially a 2018 30th round draft pick in Jack Herman, but he does need to prove himself again this year and against better competition, before he can be viewed as a top 30, or close to, prospect:

Samuel Inoa, a catcher from the Dominican Republic, is interesting, as he showed good power but the walk rate did leave lots to be disappointed.  He is older than the group of players looked at, and 2018 was his first year of pro ball stateside, and he hit .316/.433/.487 in the DSL in 2017.  Fangraphs does note that he might stick as a catcher but do talk about the hit tool.

Ji-Hwan Bae originally signed with the Braves but after their problems in regards to signing international players, Bae signed for $1.25 million with the Pirates.  He didn’t show much with power, being average in slugging and below in ISO, but did make a lot of contact as seen by the strikeout rate z-score.  Bae is most known for his speed, and he went 10/14 in 2018.  His developmental path will be one to watch.

The top performer was Herman, who slashed .340/.435/.489 with a 13.6 percent walk rate and a 14.2 percent strikeout rate.  The outfielder was by far the best of the Pirates performers, and Fangraphs wrote up,

“He’s just 6-foot tall but has a broad-shouldered frame with some room for more mass and there’s already some pop here. His arm is plus.”

There is a lot of risk in Herman, and it’s too soon to make any conclusions, but the corner outfielder did have a loud debut and he’ll need to continue to make noise to be put on the prospect radar, and it’ll be interesting to see if he can continue to hit or if he’ll struggle as Mason Martin did in his second year of pro ball.  The top performers by z-score are:

Rookie: Appalachian League (Appy)

The Appy League again features some raw players, mostly recently drafted high schoolers or international signings coming through the system.  The league lasts after the draft in June and ends in September.  The most notable name for the Pirates would be Conner Uselton, the Pirates second-round pick in 2017.  Unfortunately for him, he struggled most of the year after playing just two games in 2017 because of injury.

The only plus last season for Uselton was the strikeout rate, just 17.7 percent, but he slashed .225/.280/.250 in 175 plate appearances.  Fangraphs gives the arm a 60, which is above average, and he has future 70 raw power, so there’s still hope that now even further removed from injury Uselton will start to hit.  But it needs to happen soon.

One of the best performers was Sherten Apostel, who slashed .259/.406/.460, with the only drawback being the 24.0 percent strikeout rate.  The third base prospect was traded in July alongside Taylor Hearn for Keone Kela.

The best performer in the Appy League for the Pirates was Jonah Davis, who hit .306/.398/.612 with 12 home runs in 51 games and 241 plate appearances.  His 24.5 percent strikeout rate was high, but the 15th rounder from Berkley hit for power.  He was a bit old for the level and with the lack of pedigree, Davis will need to show more, and Fangraphs wrote:

“Davis has easy plus raw power from the left side but is a LF/DH-only defender and he struck out a ton in college”

For Davis, the bat will need to continue to play, and with the way PNC Park is in left, perhaps he’s more a RF/DH only and the bat will have to be well above average to start.  Davis is starting 2019 in Greensboro.  The Total_Z scores are:

The numbers are not adjusted for park and league and some of the players above have since been traded or released since the start of the 2018 season.  The biggest names to watch in these low levels are Carlos Arroyo, Juan Pie, Samuel Iona, Jack Herman, Ji-Hwan Bae, and Jonah Davis.  There are some positional and defensive concerns among this group, primarily with Iona and Davis.  Conner Uselton had a rough first season and will hopefully bounce back in 2019 and show why the Pirates took him in round two.

*All numbers and scouting reports from Fangraphs