Champ or Chump: Casey Mize

Rick Lucks takes a deep look into the value of top pitching prospect Casey Mize in fantasy baseball redraft leagues for 2020. Will he be a difference-maker as soon as this season?

One of the secrets to perfect in-season fantasy management is to look at your league's transaction list every single day. You may not have been the first to scoop up that hyped prospect or breakout veteran, but you can still benefit from most of their stats if their current owner abandons them after a subpar performance or two.

Casey Mize is one such name you should be on the lookout for. Mize was must-see TV when he made his highly-anticipated debut for the Tigers against the White Sox, but he failed to complete five innings and exited the game with an ERA of 6.23. Owners were likely expecting more from the first overall selection in the 2018 Amateur Draft, potentially inspiring them to throw him back to the waiver pool. Mize is only 55% owned in Yahoo! leagues as of this writing.

Cutting him after one start would be a mistake. The 23-year-old Mize showcased the excellent stuff that helped him become MLB Pipeline's eighth-ranked prospect before the season, and his seven strikeouts against zero walks were impressive despite the inflated ERA. Continue reading to find out more about what makes this kid so special.

A Scout's Total Package

As you might expect from a guy who was drafted first overall, scouts like everything about Casey Mize. Check out these scouting grades from FanGraphs as an example:

We see an above-average fastball that has been clocked as high as 97 mph. We see an above-average split that is projected to become a plus pitch in the future. We see a slider that is already a plus pitch in the Show. Best of all, we see a cutter that already ranks as a plus-plus pitch. Prospects with stuff like this generally have no idea where it's going, but Mize already has above-average MLB command with room to improve it further. It's strange for a prospect not to throw any kind of changeup, but Mize already features four plus pitches with the control to utilize them effectively.

MLB.com also loves Mize's stuff, but they grade it out a little differently. Take a look:

Mize's heater is already regarded as a plus pitch here, likely because his cutter is factored into it as opposed to receiving its own grade. Mize's 2019 scouting report notes that he can turn his mid-80s slider into an upper-80s cutter at will, which is the only time his cutter is referenced specifically. Mize's split gets a 70 grade instead, with scouts noting that it provides "outstanding late tumbling action generating both whiffs and weak contact." Strong 60-grades on his slider and control complete the analysis.

Initially, this author was concerned that scouts saw Mize's cutter as a variation of his slider, as many young pitchers struggle to maintain consistency when their offerings blur together. Pitch Info was able to detect five distinct pitches in Mize's first start: 27% cutters, 26% splitters, 18% sinkers, 16% fastballs, and 12% curves, meaning that his sliders were likely classified as cutters. Statcast saw four distinct offerings: a four-seamer (34.2%), slider (27.4%), split (26%), and curve (12.3%). Again, his slider and cutter were apparently indistinguishable.

This is something to watch moving forward, but we also have to remember that pitch-tracking technology is not foolproof. A quick look at Mize's 2019 MiLB performance reveals that he rarely if ever struggled with his consistency.

2019 in Review

Mize hurled a handful of innings in his draft year of 2018, but 2019 was his first real exposure to the rigors of professional baseball. He began the campaign at Hi-A (Lakeland), where he absolutely dominated to the tune of an 0.88 ERA and 2.60 xFIP over 30 2/3 IP. He struck out 28% of the batters who faced him against a walk rate of just 4.7%, suggesting total mastery of the level. He also held opposing batters to a likely-unsustainable BABIP of .155, though the combination of a 40.6 FB% and 32.1 IFFB% suggested some level of contact management ability.

The performance earned Mize a callup to Double-A (Erie), where he threw a no-hitter in his first start. Unfortunately, he missed about a month with right shoulder discomfort and scouts thought it affected both his stuff and command upon his return, leading to an August shutdown. His 3.20 ERA and 3.13 xFIP over 78 2/3 IP were still solid, and the fact that his K% declined to 23.5 was mitigated by a 14.1 SwStr% that was only slightly lower than the 14.6% figure he put up in Lakeland. His 5.6 BB% was very good for a young pitcher in his first exposure to Double-A, though his BABIP climbed to .294.

It's also worth noting that Mize went from an extreme pitcher's park to a hitter's paradise upon his callup. Lakeland's 0.900 HR factor ranked in the 19th percentile of all MiLB stadiums per Baseball Prospectus, while Erie's 1.378 HR factor ranked in the 77th despite the power explosion at Triple-A. Likewise, Lakeland suppressed BABIP with a 0.979 park factor that ranked in the 13th percentile, while Erie was fairer at 1.003 (29th percentile). Such a dramatic change in environment could explain why Mize didn't quite live up to his performance at Lakeland right away.

Conclusion

This author remains skeptical of Detroit's status as a contending team, even if the club is clearly going for it by calling up top prospects like Mize. As such, Mize may not get the offensive, defensive, or bullpen support of pitchers on other teams. That said, it's rare for a pitcher to have both command and a full repertoire right out of the box, and Mize needs to be owned in a lot more than half of leagues. If a rival discarded Mize after an unsatisfactory line in his first start, scoop him up and thank your fellow owner for the gift.

Verdict: Champ (based on strong stuff, plus command, and widespread availability)

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