Background

This is a short post crafted to show how the Astros' recent trade acquisition Josh Hader stacks up versus the organization's other minor league lefthanded starting pitcher candidates using the Fielding- and Ballpark-Independent Outcomes system that I have published results from here previously.

Methods

The following stats were computed for each of the minor league lefthanders through full-season league games of August 5th:

1. BB&HBP %: the sum of walks allowed and hit batsmen, divided by batters faced
2. K %: the sum of walks allowed and hit batsmen, divided by battters faced
3. LD&OFFB %: the sum of line drives allowed and outfield flyballs allowed, divided by the number of nonbunted batted balls
4. OFLD&OFFB Pull %: the number of line drives and flyballs hit to the batter's pull-field third of the outfield, divided by the total number of line drives and flyballs hit to the outfield.

Each pitcher is then rated versus their starting-biased lefthanded pitching peers who competed at the same level(s) based on how many standard deviations (SDs) better or worse the pitcher was versus the average for said stat at the same level(s). A 50 score denotes level-average performance (in the 50th percentile, equaling or bettering 50% of lefty peers), a 60 score denotes 1 SD better than level-average performance (equaling/bettering 83% of peers), a 70 score denotes 2 SD better than level-average performance (equaling/bettering 97% of peers), a 40 score denotes 1 SD worse than level-average performance (equaling/bettering 17% of peers), a 30 score denotes 2 SD worse than level-average performance (equaling/bettering 3% of peers). An Overall Score is also computed as an amalgam of those 4 stats as is an Age Score which quantifies how young the pitcher is relative to level peers, again using the same rating scheme as above.

Results

In the table, the percentage of lefthanded level peers equaled or bettered can be found in parentheses under each score. Green cells indicate a score that beat level-average by at least 1 SD, while yellow cells indicate a score that trailed level-average by at least 1 SD.

Hader grades out as a bit worse than level-average at control and at avoiding line drives plus outfield flies while rating a bit better than level-average at strikeouts. Where he particularly excels is in avoiding being pulled on his outfield line drives and outfield flyballs, posting just about the best result that you'll see for a full-season league pitcher with that large of a batted balls sample. Hader rates beyond 2 SD better than what is average for an A-ball lefty starter, and this statistical aversion to being pulled aerially helps minimize his risk of surrendering home runs and other extra-base hits in spite of allowing a higher than typical percentage of flyballs plus line drives (Hader has allowed 15 doubles, 2 triples, and 4 homers over 388 batters faced). Hader's strong showing on the aerial pull stat and his nearly average scores on the other 3 metrics allows his Overall Score to beat 82% of his peers while being younger than 97% of them. Among the listed Astros' minor league lefthanded starter candidates, Hader trails only Brian Holmes (his injury-condensed campaign has only recently resumed) and Brett Oberholtzer (we're now witnessing some level of carryover of this performance to MLB).

Summary

Josh Hader is exceptionally young relative to his level of competition and currently grades out rather well versus his peer group of A-ball lefthanded starters in terms of overall performance on the studied fielding- and ballpark-independent outcome stats. In terms of his prospective development as a pitcher, control and line drive plus flyball avoidance would stand to be the 2 current areas to target for incremental improvements, with any steps forward in the latter category serving to offset some anticipated regression back toward his peers in aerial pull rate.

What about Kyle Smith?

Before the Justin Maxwell trade, I published a post at the SB Nation prospects site minorleagueball that showed how Kyle Smith and others of John Sickels' more highly-rated starting pitcher prospects had performed on these same metrics through games of July 15 and how they had changed likewise versus 2012. If you are curious as to where Smith stood then, click the link above and scroll down to the "K. Smith (KC)" rows towards the bottom of the 2nd and 4th tables in that report.