In my last post, I went over how context is important in minor league stats, reviewing pitchers in the Royals organization. I put their numbers in context by using standard deviation to paint an image on how well pitchers performed adjusted to the league they played in.
This becomes way more extreme in the minors. You’ll have a league that favors hitters strongly, such as the Pioneer League (Rookie) with a league wide ERA of 5.65. Then a league that favors pitchers like the Southern League (AA) with an ERA of 3.60. That’s quite a difference.
These differences have to be strongly considered when evaluating a prospect. For good measure, look at Idaho Falls Chukars pitcher Holden Capps. On the surface, a 5.49 ERA and 4.80 FIP does not look all that great. But because he pitched in the hitters paradise known as the Pioneer League, Capps was actually had a better season than two-thirds of the league.
I figured, why not make one for hitters? Pulling the data for every qualified hitter in the minors (around 3,000+ players), I compared them to their respective league’s (Pioneer, Pacific Coast, Arizona, etc.) wOBA using standard deviation to create a z-score. Here are some interesting things I found.
AAA- Omaha Storm Chasers
- The Pacific Coast League is a very hitter-friendly league with a league average of 5.05 runs per game. The Storm Chasers were behind the mean though, scoring 4.45 runs per game, 3rd lowest in the Pacific Coast.
- Jorge Soler was far and away the best hitter in Omaha this year. Among hitters with at least 150 plate appearances, he had the 12 best wOBA in the PCL, standing at .408. His z-score (last column) ranked in the top 7% of all qualified hitters in minors.
- The only others hitters that were above-average in Omaha were Frank Schwindel and Raul Mondesi.
AA- Northwest Arkansas Naturals
- Nick Dini quietly had a very good season for the Naturals, batting .310/.381/.380. His .352 wOBA ranked in the top fourth of the Texas League.
- Outside of Nick Dini, Donnie Dewees was the only above-average hitter for the Naturals this season.
- Anderson Miller and Nicky Lopez struggled after their promotions. Both hit very well in A+ (Miller- 132 wRC+, Lopez- 125 wRC+), but couldn’t quite continue that success to AA (Miller- 54 wRC+, Lopez- 72 wRC+).
A+- Wilmington Blue Rocks
- Chase Vallot and Anderson Miller hit very well in a pitchers-league. Minimum 150 plate appearances, Vallot posted the 13th highest wOBA in the Carolina League, Downes the 15th highest. This gave Vallot the 4th highest z-score in the Royals organization, Downes the 8th highest.
- The Wilmington Blue Rocks scored 3.94 runs per game, the second lowest mark in the Carolina League.
- Chris DeVito didn’t hit well after his quick promotion. In 131 plate appearance with the Low-A Lexington Legends, DeVito hit .347./.374/.702. But in Wilmington, DeVito couldn’t make good contact consistently, hitting .240/.287/.382. DeVito’s -14.58 z-score in Wilmington ranked in the bottom third of the Royals organization.
A- Lexington Legends
- Lexington easily had the most above-average hitters out of any Royals minor league team, with 7 of the 12 hitters ranking above-average. This translated to the second most runs in the South Atlantic League.
- John Brontsema’s z-score not only ranked as the top mark on the Lexington Legends, but was the highest in the Royals organization by a decent margin. It also ranked 17th out of 3,000+ minor league hitters. Never heard of him? He was the Royals 26th round pick last year out of UC Irvine. The infielder raked in 190 plate appearances with the Lexington Legends, hitting .323/.416/.484.
- Three young prospects show up as being considerably above-average (Khalil Lee, Emmanuel Rivera, and Gabriel Cancel). Their z-scores all ranked in the top 17% of the minor leagues, with Rivera ranking in the top 5%.
Rookie- Idaho Falls Chukars
- The Idaho Falls Chukars are a very interesting case. The Pioneer League has the highest runs per game out of all leagues at 6.57 (next closest in Arizona League at 5.38). The Chukars rated near the top of league too, scoring 7.07 per game.
- Only four Chukars have a wOBA south of .350. This may seem great on the surface, but playing in a hitter’s paradise sets the standards higher for players. For example, it looked like Amalani Fukofuka had a solid season in Idaho Falls, but his .359 wOBA was below the standards for the league he was playing in.
- Among qualified hitters, Darrell Miller had the second highest wOBA in the Pioneer League. Additionally, he had the highest wOBA in the Royals organization (6th highest z-score).
Rookie- Burlington Royals
- Rookie Michael Gigliotti was very comfortable in the Appalachian League. Among qualified hitters, his .424 wOBA ranked second there. Gigliotti had the 7th highest z-score in the organization.
- The Burlington Royals struggled to put runs on the board. They ranked 9th out of 10 teams in runs scored.
- Former highly touted international prospect Jeison Guzman really had his troubles in his second professional season. He had the third worst wOBA in the Appalachian League, hitting .207/.286/.249 along the way.
Rookie- Arizona League Royals
- The only three hitters that came in at above-average for the AZL Royals were all drafted this year (Nick Pratto, MJ Melendez, and Tyler James).
- Isaiah Henry, the Royals 21st round pick this year, had the 4th worst z-score in the organization. He hit .148/.205/.244 in his first professional season.
Rookie- DSL Royals
- It was a tough season for DSL Royals hitters as a whole. The team scored 2.79 runs per game. Worst in the minor leagues across all levels.
- The best hitters on the DSL Royals were Ismaldo Rodriguez and Rubendy Jaquez. Rodriguez hit .223/.356/.348, Jaquez hit .267/.362/.338.
- The worst hitter on the DSL Royals was Paul Mondesi. His z-score was also the worst in the organization.