Joe Musgrove’s MLB data agree with scouting reports so far

Houston Astros starting pitcher Joe Musgrove began his Major League career in stunning fashion - three dominant appearances against the Blue Jays and Rangers (both top 10 offenses by runs scored) in which he produced a 21/2 strikeout-to-walk ratio and helped hold those teams to only three total runs in his 18.1 innings pitched.

He followed those appearances with a fourth outing of a more startling fashion. On Thursday, the Orioles’ own high-powered offense hit three home runs against Musgrove, plating eight total runs in his 5.1 innings pitched. Rookie pitcher implosions certainly aren’t unusual, and without a sudden, glaring change in his repertoire, this one outing of poor results obviously won’t negatively impact his long-term outlook.

However, his first three outings also aren’t likely to be representative of his long-term prospects - a true-talent 43 FIP- would be, for all intents and purposes, impossible. On the other hand, he does also have the gaudy Minor League track record that breeds unreasonable expectations.

Over the last two seasons, he’s pitched a combined 186 innings with a 2.61 RA/9, 49.3 percent groundball rate, and 23.0 K-BB percent across four fairly hitter-friendly Minor League levels. Perhaps most notable about his profile is his walk rate - he allowed only 18 total walks, 2.5 percent of plate appearances, over that time. This season, prospect lists have started to take notice. After being ranked #83 on Baseball America’s preseason Top 100 Prospects list, he was bumped up to #32 on their Midseason Top 100 Prospects list.

Based on various public scouting reports, we can paint a picture of Musgrove’s repertoire. Below is a compiled list of the most prominent scouting reports available. The Baseball America entry is extrapolated from the language used in describing the tools - “above-average” is a 55 grade, whereas “plus” is 60. FanGraphs’ entry uses their report’s median outcome grade.

What stands out immediately is MLB.com’s mention of two distinct breaking balls, something the other reports don’t include. Have we seen a curveball since his promotion, in addition to Musgrove’s oft-referenced slider? Brooks Baseball says yes, and we can even consult the PITCHf/x data itself to find the curveball. I’ve circled the rough locations of each pitch below.

It does seem like there is a fairly tight cluster of sliders by movement and velocity and a separate cluster of pitches that are slower and with more drop (even if there is a larger spread in horizontal movement).

We’re still dealing with small samples here, but individual characteristics of each pitch - velocity, movement, command - become evident more quickly than opponent-dependent numbers like ground ball rate, strikeouts, or walks. There are any number of reasons why the quality of a pitch can change, from an injury to a mechanical adjustment, but from these data, can we tell how good these pitches currently are? To tackle this sabermetrically, I’ve attempted to create an objective scouting report using PITCHf/x. I created a similar report once before when discussing Phillies’ starter Jerad Eickhoff, and I thought it might be fun to do so with Musgrove as well.

Baseball’s 20-80 scouting scale is loosely based on the 68-95-99.7 Rule in statistics, referencing the percentage of values contained within one, two, and three standard deviations of the mean of a normal distribution. A 50 grade player is considered league average, a 60 grade player is roughly one standard deviation above average, and a 40 grade player is roughly an equal distance below average.

To accomplish this objective scouting report, I used Baseball Prospectus’ PITCHf/x leaderboards (which use the same dataset as Brooks Baseball) to take the sample of starting pitchers who have thrown at least 200 four-seam fastballs, sinkers, sliders, curveballs, or changeups in 2016. For each pitch type, I found the average and standard deviation of several qualities of the pitch (velocity, horizontal movement, vertical movement, and strike percentage).

With this information, I created Z-scores comparing Musgrove’s pitches to the rest of the league and converted those to “grades” by treating every half of a standard deviation as half a grade (5 points) above or below 50. To create a total grade for each pitch, I simply averaged the four components mentioned above.

There are obviously some small sample problems at work here - it seems reasonable to expect that he doesn’t throw strikes at a 20 grade level with his curveball or at an 80 grade level with his sinker. Another issue is that written scouting reports, like the ones mentioned earlier, haven’t really adjusted their fastball grades as velocity has increased league-wide.

While Musgrove’s 92.8 mph four-seam fastball is exactly league average (92.8 mph for a starting pitcher), sitting 92-93 mph and hitting 95 is still often graded as above-average velocity. Because of this, the fastballs could receive something like a half-grade bonus if one is so inclined. Additionally, the changeup doesn’t grade out as anything special, but it has demonstrated an above-average velocity difference with the four-seam fastball, which is a beneficial feature.

In all honesty, this is still a blunt tool that doesn’t account fully for command, deception, or other difficult to ascertain parts of pitching. However, there are some things that can be gleaned - notably, Musgrove has seen a ton of vertical movement across the board. His slider has so far appeared better than advertised, seeing a lot of two-plane movement while being thrown for strikes. The infrequently-thrown sinker has seen the most drop of any pitch while hitting the strike zone.

Using what we’ve seen in his four appearances, Musgrove has above average command of two above average fastball variations, a plus breaking ball, and a fringe-average offspeed pitch. Scouts project Musgrove as a likely #3/4 pitcher in a starting rotation, and this simple report agrees with that assessment. Even through only four appearances, his PITCHf/x data are already mostly in line with what scouts have said all year.

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Spencer Bingol is a Contributing Editor at Beyond the Box Score. He can also be read at Crashburn Alley. You can follow him on Twitter at @SpencerBingol.

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