I took on the role of one major league organization's scouting director (drafter) in the May 31st Minor League Ball 4-Round Mock Draft, and to help with that I ran many of the top collegiate draft-eligible starting pitchers through a variation of the statistical evaluation system that I use to assess performance of professional pitchers (the same one I share results from on these very pages).
Prior readers of my work recall that I assess three unique facets of performance: Control Rating (using BB+HBP%), Strikeout Rating (using K%), and Batted Ball Rating. Typically I evaluate every pitcher in a league and then rank them accordingly. But to get the Batted Ball Rating requires capturing the play event description of tons of plate appearance (PA) outcomes versus conference starting pitchers and that just wasn't practical this time around. So instead I just captured the details of all 2014 PA against the 29 draft prospects and ranked their batted ball performances within the group. The Control and Strikeout Ratings were determined within each unique group of conference starting pitchers as I have typically done before. I then estimate what the Overall Performance Rating would be based on those three component ratings (with minor leaguers, I generate the Overall Performance Rating first and then compute the 3 component ratings). One inconvenience is that base hits that reach the outfield are not distinguished in the collegiate play-by-play descriptions as being a groundball (GB), line drive (LD), or outfield flyball (OFFB). My compromise solution is to assume for a given hit type (1B, 2B, 3B, or HR) sent to a given third of the outfield (pull-field-third, center-third, opposite-field-third) that the pitcher's overall breakdown of GB/LD/OFFB matches that which is typical for the event in the lower minor leagues. That's not nearly the deal breaker that may seem in that the outs form the bulk of the pitcher's batted ball sample- just appreciate that if a pitcher was generally better than average at avoiding line drives on their hits then they probably performed a little better on batted balls than my numbers would suggest (or worse, if they fared worse than average at that). Ultimately every fair, non-bunted batted ball against the pitcher gets classified into one of 10 categories that you'll see later and they are charged with the number of runs that each of those events is worth on average in the minors. And then the pitchers get ranked from best to worst on a runs avoided basis per batted ball.
The study subjects were twenty-nine 2014 NCAA Division I pitchers who started at least some games and had moseyed their way onto the Baseball America Top 100 Draft Prospects List or the MLB.com one. For each parameter, I'll express the result as both a score on a 20-to-80-style scouting scale (50 is average, >50 is better than average, any 10-point change amounts to one standard deviation) and as a percentile of peers beaten.
Here are the pitchers ranked from best to worst on overall performance.
Let's cut to the chase and dissect 1st overall pick candidate Rodon. He was well above average at the strikeout, slightly below it at control (a high HBP rate contributed to this outcome), and a decent amount under it on batted balls. Though Rodon was easily an above-average collegiate SP per his Overall Performance Rating, he ranks roughly in the middle of this select group of 29 hurlers. Among other early 1st round candidates, Nola was mostly an elite strikeout specialist, the same was true for the now rehabilitating Hoffman, Freeland was both a control and strikeout extremist, Newcomb displayed a combination of plus strikeout ability and plus batted ball performance, Finnegan was a feast-or-famine type who was just as sexy at the strikeout as he was unsexy on batted balls, while Beede altogether preferred to keep the ball out of play whenever possible by walking and whiffing batters at comparably high rates.
Performance Ratings: LHB and RHB
And below is how a featured first-round-biased subset of those pitchers rated when I examined the 29 pitchers' 2014 performance against only lefthanded batters (LHB) or only righthanded batters (RHB).
The table shows that the southpaw Rodon's batted ball issues in 2014 were relegated to RHB; he'd rate in only the 5th percentile of the 29 top prospects on RHB batted balls. The righty Nola sported a similar wart versus his opposite-handed nemeses. Looking at more typical metrics (batting average, slugging percentage, isolated power), the duo seemed to roughly break even on batted balls versus opposite handers but professional hitters would not figure to be so compassionate to them were they to replicate those sorts of performances in the minor or major leagues.
With RHB and LHB splits occasionally on the volatile side due to sample sizes, park effects, and so on, it seems wise to also examine how Rodon and Nola fared in 2013.
Rodon and Nola: 2014 versus 2013 Performance
As before, the Control Rating and Strikeout Rating of each for 2013 were determined versus their 2013 conference SP mates. To get the 2013 Batted Ball Rating, their 2014 batted ball was simply replaced with the 2013 data and lumped in with the 2014 batted ball data of the other 27 starters under review.
Rodon's overall performance declined in 2014 versus 2013, and almost entirely as a result of how he fared versus RHB. A drop in his RHB Strikeout Rating was accompanied by his RHB batted ball performance falling from below average in 2013 to well below it in 2014. As a result of that drop in performance versus RHB, Rodon's Overall Performance Rating versus all batters dropped from the 99th percentile in 2013 to the 77th percentile in 2014.
Versus the 2013 values, Nola's Control Rating fell from well above average to slightly above it, his Strikeout Rating increased from well above average to elite territory, his LHB Batted Ball Rating fell from well above average to well below it, and his RHB Batted Ball Rating rose from average to well above average. In spite of all that movement, Nola's Overall Performance Rating versus all batters held steady from 2013 to 2014 at the 99th percentile.
Comparing Nola's 2014 ratings to Rodon's 2013 ratings shows that the 2014 version of Nola performed quite similarly to the 2013 version of Rodon; each rated nearly average at control, ultra-elite at the strikeout, above average on same-handed batted balls, and below average on opposite-handed batted balls. So in some respects, Nola became Rodon in 2014, while Rodon fell back towards the pack of collegiate starters a bit.
At this next detailed level of analysis, which amounts to looking at a pitcher's batted ball spray distribution table, one can often spot the seed whence a good or bad Batted Ball Rating sprang. The numbers in parentheses in the column headers reflects how many runs each occurrence of said event is typically worth in a minor league game, on average; that reminds us which outcomes are to be welcomed or avoided by the pitcher.
In looking at a typical pitcher's spray chart in this fashion I would hazard that in most cases we are seeing 65% to 80% fastball outcomes. Given Rodon's heavy slider usage, he would stand to fall near the low end of that range. Video analysis would be required to cut to the core of whatever 2014 issues Rodon may have had with RHB batted balls, but one would hypothesize that the poor results reflect some mix of square-uppable fastballs and hanging sliders. The elevated 9% Pull-Third OFFB% by RHB would be particularly worrisome for a possible future inhabitant of MinuteMaid Park given the close proximity of the Crawford Boxes in left. One can see similar trends in the 2013 data in comparing it to the 2014 numbers. Rodon has the statistical profile of a southpaw who will experience some measure of loud contact from RHB as a professional, and thus it would serve him well to maintain a plus to plus plus strikeout performance against them to offset that probable weakness.
As a consequence of Nola's GB% falling across the board (not unsurprising given the increase in K% he enjoyed), he sported a very high OFFB% versus LHB and surrendered a correspondingly high 10% rate of the very dangerous Pull-Third OFFB to them. Looking at the 2013 versus 2014 LHB rates of OFFB by zone, a fair chunk of Nola's exaggeratedly high 20% rate of center-third OFFB in 2013 jumped over to pull-third in 2014 (it does seem more logical that some of those should wind up in the pull-field).