Reminder as to How Performance is Graded
The Fielding and Ballpark Independent Outcomes evaluation system charges each minor league pitcher with the number of runs shown in the table below for each such event they allowed in each league (bunts, foulouts, and plate appearances with a pitcher batting are ignored). Summing that over all 12 event types and dividing the result by the number of batters faced yields a single number of runs per plate appearance that quantifies how well the pitcher should have performed in that league. Each pitcher then gets graded versus a core group of starting-biased pitchers in that league who met some minimum batters faced criteria. At that point the pitchers of a league can be ranked from best to worst on performance and they receive a Performance Score that expresses how well they fared. Note that whether an individual pitcher surrendered a hit, home run, or runs on a plate appearance is completely ignored in grading their performance.
I also break the performance of each pitcher down into three sub-categories to identify their relative strengths and weaknesses: Control Subscore, Strikeout Subscore, and Batted Ball Subscore. Those 3 elements explain 23%, 43%, and 34% of a pitcher's Performance Score, respectively, in a typical league. An Age Score is computed to quantify how young the pitcher was relative to league starting-biased pitchers; this is used purely as a frame of reference when interpreting a pitcher's results.
A 50 score on any measure amounts to matching the league's average value (the pitcher topped or equaled 50% of peers), a 60 amounts to 1 standard deviation (SD) better than league-average (topped/equaled 83% of peers), a 70 amounts to 2 SD better than league-average (topped/equaled 97% of peers), a 40 amounts to 1 SD worse than league-average (topped/equaled 17% of peers), and so on with any 10 point swing in a score amounting to 1 SD.
The Quad Cities and Lancaster pitchers whose names appear in the tables that follow averaged at least 10 batters faced per game in April, and thus qualify as "starting pitchers" for the sake of the analysis. Table values that bettered the league average mark by at least 1 SD are highlighted in green text ("very good") whereas those that trailed it by at least 1 SD are in red ("very bad").
Quad Cities River Bandits
Thurman tops the leaderboard for April with a half SD to full SD improvement in all 3 subscores versus his 2013 short-season debut; batted balls remain the potential red flag as even now he would rate in the 16th percentile of Midwest League pitchers in that department. Grills holds somewhat steady versus 2013, with his nearly 1 SD rise in control offsetting a nearly 1 SD fall in strikeouts. The leap from short relief to tandeming has substantially lowered Sanudo's Strikeout Subscore with the other two subscores staying pat. Though Houser's control rating has declined relative to 2013, he is performed slightly better overall in April thanks to improvements in the other two categories. Gustave's April control performance has been surprising, particularly given the considerable push upwards from the Appalachian League. Here we have a first look at Emanuel under this microscope; at this seminal stage, he rates rather high on control and equally low on batted balls. Feliz' control rating took a nosedive versus the 2013 number as he labored through five April appearances before landing on the disabled list. Lee's two former strengths, the K and the batted ball, have lagged a bit in April in jumping from Greeneville directly to Davenport.
The table below shows the breakdown of each hurler's batted balls for April.
Thurman's high percentage of pulled outfield flyballs would largely explain his poor 39 Batted Ball Subscore. Emanuel's similarly low 41 Batted Ball Subscore may not be quite so concerning in that it seems fueled mostly by what could be a flukishly high line drive rate by league standards (nor did we see him perform poorly on those grounds during 2013). Houser's excellent 60 Batted Ball Subscore was mostly a product of his 62% groundball rate and 9% infield fly rate.
Smith rode a much improved April Batted Ball Subscore into the 90th overall performance percentile and on to AA with his recent promotion. Groundballers Hauschild and Westwood rate similarly with the exception of the strikeout column where the holdover Hauschild currently enjoys an edge over the Quad Cities-bypassing newcomer. Hader's April numbers are in rather stark contrast to his 2013 full-season marks; as his strikeouts have soared his batted ball outcomes have plummeted a comparable amount. Not much has changed with McCullers' April versus 2013 outside of a bit of a decline in strikeout rating. Smallish drops in all 3 subscores have pulled Velasquez' Performance Score down a decent amount, with batted balls remaining the future concern. Appel's abbreviated April grades out almost identically to his 2013 summer debut. Even as the worst performer of the eightsome per this system Devenski deserves a pat on the backside for rating roughly average by California League starter standards.
So here is where we realize that much of Smith's numerical improvement in batted balls versus 2013 is likely unsustainable - contrast the 7% overall line drive rate and 11% infield flyball rate versus the league's average marks at the bottom. It is surprising to see McCullers being pulled so frequently on outfield flyballs this April; we saw that in 2013 with Velasquez but not with McCullers. Westwood sports a nifty 66% overall groundball rate with hardly any pulled outfield fly balls.
April data from starting pitchers of Corpus Christi and Oklahoma City will be posted soon. I have become efficient enough at the related processes that I plan to periodically break down individual hurlers during the season using the system; in these featured subject posts I will show how their professional performance marks have changed over time from their very first batter faced to their most recent one.