Prospect Scouting & Stats — Pitcher RPM FB

Today, I’ll continue my look at prospect scouting and stats, but our metric of the day is completely objective — RPM FB, which is revolutions per minute of the fastball, otherwise known as spin rate. We know that the spin rate of a prospect’s fastball does correlate positively (0.19 correlation) with strikeout rate, so all else being equal, you want to see a higher RPM FB. With that in mind, let’s dive into the RPM FB prospect leaderboards, discussing the top seven as sorted by the metric and then FV.

For context, in 2019, the leading average fastball spin rate from those who threw at least 50 fastballs was 2,889, followed by 2,746, and then a host of players between 2,600 and 2,700.

Knowing the top of the line spin rates in the Majors makes it even more impressive that our top man Camilo Doval throws a 2,750 spin rate fastball already. Doval ranks just 20th among Giants prospects, but it’s certainly not because of his stuff. With strong strikeout and SwStk% marks, and the ability to max out his fastball at 99 MPH, it appears that spin rate is driving his performance. Instead, its his complete lack of command, a skill he graded out at just 20, the lowest possible grade. His walk rates have sat in double digits at three of four stops, and reached 13.9% during his latest stint in High-A. As is the case with many minor league pitchers, improving his control will be key. If he does that, he could find himself in the Giants bullpen.

Julian Garcia ranks even worse among his organization’s prospects at just 26th, but this time it’s his stuff holding him back. Despite an elite RPM FB, his strikeout rate has fallen precipitously, sinking every stop since 2017. Along with declining strikeout rates is an extreme fly ball rate, which is quite a dangerous combination. The only thing going for him now is solid control, but that’s not enough at the moment. He’ll need to reverse that strikeout rate trend to put himself on the prospect map. It’s a shame he hasn’t been able to do more with that high spin fastball, but a lot of that likely has to do with the pitch’s velocity, as it maxes out at just 91 MPH.

Shane Baz is the only one in this list that was mentioned in our top 100 list, even though he fell outside that 100. Baz’s RPM FB matches with the pitch’s grade, which stands at 60 at present and 70 in the future. Oh, and he maxes out at 100 MPH, though sits 92-96. Even with the elite fastball, the strikeout rates haven’t been overly impressive, sitting in the mid-20% range. That’s fine, but nothing special. Considering he has yet to push his walk rate into single digits and he has suddenly become an extreme fly ball pitcher, he’s got a long way to go before fantasy owners should care about him.

During his second tour of Double-A, Braves prospect Kyle Muller’s control disappeared. His strikeout rate rose marginally, supported by a small jump in SwStk%, but all those walks along with a fly ball tendency raises red flags. Perhaps the loss of control was a fluke, but it did come in his largest sample size, so we’ll have to wait until minor league games are back to see what happens with his control.

So Melvin Adon owns a perfect 80 grade fastball, near elite RPM FB, sits 96-101 with his fastball, and maxes out at 102 MPH. He transitioned to relief full-time in 2019, and it’s clear that the quality of his stuff surged thanks to the move. Unfortunately, he suffered massive control problems, plus a strikeout rate just over 30%, while very good, isn’t elite and certainly not good enough to offset the high walk rates.

For a guy with a pretty strong RPM FB, Beau Burrows‘ strikeout rate have been pretty pathetic throughout nearly all of his minor league career. He doesn’t induce a whole lot of whiffs and he doesn’t even offset the lack of strikeouts with sterling control. In fact, his walk rates have been in or just below double digits during his last three years. The Tigers must have a pretty barren system if this guy ranks as the 17th best prospect!

Finally, we have an interesting name in Giants prospect Blake Rivera. We don’t have a large sample of innings yet, despite him serving as a starter, but his SwStk% was excellent in 2019, and suggests a better strikeout rate than he actually posted. He was also an extreme ground ball pitcher, something you don’t normally get from a pitcher who generates so many swings and misses. The only issue now is his control, so yet again, his future success and ability to make it to the Majors will heavily depend on whether he could sharpen that important skill.