After being traded to San Diego, fantasy players hedged their bets on an improved version of Joe Musgrove free from Pittsburgh. So far, so good. Yes, he's only 2-2 over four starts this season but it includes the first no-hitter in Padres history and his last loss featured 13 strikeouts over seven innings giving up four hits, two earned runs, and a walk raising his ERA to 1.04 as a result. 

Before delving into how Mus(t)grove improved his strikeout rate and performance in his first 26 innings, a tweet for the visual crowd like myself: 

Through his first 26 innings, he owns a robust 37:3 K:BB, 1.81 SIERA and 0.54 WHIP. Producing more ground balls (up over five percent) in his batted ball data should help mitigate regression to the mean. In terms of swing and miss stuff, Musgrove's improved his swinging strike percentage by three points to 17.4 percent in 2021 fueled by a massive gain in O-Swing (outside the strike zone) swing rate up over ten percentage points and reducing contact. 

Transitioning to Statcast, there are some interesting results in terms of pitch usage within his arsenal. He's using his four-seam fastball only 13.4 percent of the time this season compared to a 26.9 percent in 2020. Ramping up his off-speed offerings and cutters, his pitch mix may be the reason behind his strong start. Here are his swings and misses so far: 

Taking this into account, now view his usage variances from 2020 to this season:

For context, Musgrove's throwing pitches in the strike zone less often while giving up more zone contact (remember migration comes for everyone) but the gains in chase rate (up 7.6 percent) and reduction in chase contact (down by nine percent) create more whiffs. How many more? His swing percentage sits almost three percent above last year and his whiff percentage has improved by four percent. 

Knowing he's throwing less fastballs and sinkers, can this be sustained all season? Perhaps. Illustrated below by his pitches and their expected statistics (2021 only) with strikeout predictors included. For the purposes of this chart: 

    - xBA - expected batting average

    - xwOBA - expected weighted on-base average

    - Whiff% - swings and misses percent of total swings

    - Put Away% - pitch percent resulting in a strikeout

Pitch Usage

2020

2021

xBA

xwOBA

Whiff%

PutAway%

K%

Slider

24.2%

27%

.114

.071

58.6%

42.3%

68.8%

Cutter

6.4%

24.8%

.318

.297

28.6%

21.1%

18.2%

Curve

19.9%

19.9%

.203

.127

34.5%

29.2%

41.2%

4-seam

26.9%

13.4%

.517

.845

10%

0

0

Change

10.2%

10.6%

.127

.000

30.4%

50%

20%

Sinker

10.7%

4.4%

.217

.000

22.2%

50%

20%

Please remember this remains a small sample size. Improved rates with his four-seamer actually could insulate Musgrove from too much pending migration to the mean. Or using more curves and change-ups dependent on matchups. Not sure he can use his slider more than any other pitch over a full season. Of course, San Diego can protect him from overuse. 

Dinelson Lamet 's coming off the injured list this week and the Padres may enact a six-man rotation. Musgrove's recorded more than 100 innings three times in his career (2017, 2018, 2019) and greater than 150 innings once (170.1 in 2019). However, the jump in workload caused a late start and he missed outings in 2020 as a result. 

Musgrove's been terrific to this point. He's outperformed pitchers taken ahead of him in drafts. Apply the fact he may only get one start a week going forward to keep him healthy over the full season and for San Diego fans, a run deep into the playoffs. Bank the numbers he's put up to this point, track how his pitch usage evolves over the course of the season and heed any warning signs of fatigue if they surface. 

One cannot ignore the absolute monster start to 2021 by Musgrove evidenced by his swing and take chart: 

He's emerged as a front line starter and just needs to prove he can accrue enough innings to be a starting pitcher two in future drafts. All he needs, better performance from his four-seam fastball and health. One can be fixed by deployment, the other remains out of fantasy player's hands. Best of all, enjoy the ride:

Statistical Credits: 

Fangraphs.com

BaseballSavant.com