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What are the most valuable kinds of fantasy baseball rookies?

May 28, 2020

How can you find the next Pete Alonso?

Fantasy baseball has a major learning curve as there are hundreds upon hundreds of potentially fantasy-relevant players. Heck, who had ever heard of Whit Merrifield, Mike Clevinger an Kirby Yates before they seemingly came out of nowhere to become fantasy baseball mainstays? The most challenging, of course, are the rookies, as there are some like Vlad Gurrrero Jr. and even Mike Trout who struggle out of the gate despite being considered all-time prospects. But it seems as though there is a pattern. Let me explain.

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Successful Rookie Hitters

First, let’s take a look at the three most successful rookies from each of the past five seasons. I’ll list their prospect ranking (according to Baseball America before they were called up) along with their previous season’s age and minor league stats (BA/OBP/SLG and level). Afterward, I’ll walk you through the patterns that stick out.



  • Juan Soto (#56 prospect, 19 Yr, .292/.406/.517, 5 SB in A/A+/AA)
  • Ronald Acuna (#1 prospect, 19 Yr, .325/.374/.522, 20 SB in A+/AA/AAA)
  • Gleyber Torres (#6 prospect, 20 Yr, .287/.383/.480, 7 SB in AA/AAA)


  • Aaron Judge (#90 prospect, 24 Yr, .270/.366/.489, 5 SB in AAA)
  • Cody Bellinger (#7 prospect, 20 Yr, .271/.365/.507, 8 SB in AA/AAA)
  • Andrew Benintendi (#1 prospect, 21 Yr, .312/.378/.532, 16 SB in 97 A+/AA gms)


  • Corey Seager (#1 prospect, 21 Yr, .293/.344/.487, 4 SB in AA/AAA)
  • Trea Turner (#9 prospect, 22 Yr, .322/.370/.458, 29 SB in AA/AAA)
  • Trevor Story (#96 prospect, 22 Yr, .279/.350/.514, 22 SB in AA/AAA)


  • Kris Bryant (#1 prospect, 22 Yr, .325/.438/.661, 15 SB in AA/AAA)
  • Carlos Correa (#4 prospect, 19 Yr, .335/.407/.600, 18 SB in AA/AAA)
  • Miguel Sano (#6 prospect, 20 Yr, .280/.382/.610, 11 SB in A+/AA)

Exit Velocity Kings

There is not a single player listed above without plus max exit velocities, but several of these players are the elite. Let’s move past the obvious studs like Kris Bryant (look at those stats!) and Ronald Acuna. They were the game’s top prospects and anyone could have pegged them to dominate from day one. Instead, take a look at the outliers of the pack: Alonso, Judge and Soto were far from can’t miss prospects.

We were all waiting for Judge’s in-game power to develop as he learned how to lay-off bad pitches. We knew, though, that if it clicked, he had league-winning power upside. Alonso was similar in that he was an older prospect with little else to his game besides the power. Sometimes it helps to look beyond the prospect rankings, as they are an indication of the total real-life package and not fantasy relevance. Alonso’s bat was MLB-ready and pushed the envelope for the Mets to play him immediately. In Soto’s case, some in the industry (FantasyPros included) were already clamoring for Soto to be a top 10 prospect because of his elite tools and inevitable upside. It just so turns out that the Nationals were in win-now mode and knew he could help them immediately.

Take a chance on players like Judge and Alonso at the end of drafts just in case they do find their way into the starting lineup out of Spring Training. It might not go well, but you’ll be cutting 20% of your drafted roster by Memorial Day most seasons anyways so you as well swing for the fences with older prospects who have absolutely terrorized minor league pitching. More often that not, minor league stats will correlate to MLB numbers even if there isn’t any defense or speed to pull up their prospect rankings.

Speed Kills

Yeah, yeah, you get it; stolen bases come in handy for fantasy baseball, hence why Billy Hamilton‘s ADP remained so high even while he was batting .210 for the Reds all those years ago. But it isn’t just stolen bases that speed helps with. Tatis, for instance, carried a .317 batting average as a rookie thanks to a BABIP well over .400. Turner batted .342 as a rookie, again, thanks to an inflated BABIP. The thing is, though, that elite-speedsters carry these staggering BABIPs much more often than anyone else because of their ability to beat out grounders in the hole or a chopper to short.

Likewise, these players often hit at the top of lineups which translates to plenty of runs by itself, but even more because of how often they can score from second on a single, first on a double or third on a fly ball to shallow center. That is three categories that speed help with, folks. But do note that each of these speed guys also had strong bat skills. None of them became excellent fantasy assets by speed alone.

Successful Rookie Pitchers

It wasn’t long ago that young pitchers were the only rookies who to have immediate fantasy superstardom. The reason was that pitchers depend more on stuff whereas hitters depend more on approach. The narrative has actually reversed, though as minor league ball-clubs are doing a better job developing hitter’s minds and bodies. Meanwhile, stud rookie pitchers are handled like glass and limited in terms of innings. Even still, there are ten below who dominated in their capped out innings all 10 have something in common that can help us target future rookie aces.


  • Chris Paddack (#66 prospect, 22 Yr, 2.10 ERA, 12.0 K/9, 0.8 BB/9, 6.6 H/9 in A+/AA)
  • Mike Soroka (#25 prospect, 20 Yr, 1.76 ERA, 10.0 K/9, 1.8 BB/9, 5.9 H/9 in A/AAA)


  • Walker Buehler (#13 prospect, 22 Yr, 3.35 ERA, 12.7 K/9, 3.1 BB/9, 6.8 H/9 in A+/AA/AAA)
  • Jack Flaherty (#53 prospect, 21 Yr, 2.18 ERA, 8.9 K/9, 2.1 BB/9, 7.3 H/9 in AA/AAA)


  • Luis Castillo (not ranked prospect, 24 Yr, 2.58 ERA, 9.1 K/9, 1.5 BB/9, 7.6 H/9 in AA)
  • Dinelson Lamet (not ranked prospect, 24 Yr, 3.23 ERA, 11.5 K/9, 4.6 BB/9, 7.4 H/9 in AAA)


  • Kenta Maeda (#50 prospect, 27 Yr, 2.09 ERA, 7.6 K/9, 1.8 BB/9, 7.3 H/9 in Japan)
  • Jameson Taillon (#29 prospect, 24 Yr, 2.04 ERA, 8.9 K/9, 0.9 BB/9, 6.4 H/9 in AAA)


  • Noah Syndergaard (#11 prospect, 22 Yr, 1.82 ERA, 10.3 K/9, 2.4 BB/9, 6.1 H/9 in AAA)
  • Lance McCullers Jr. (#77 prospect, 21 Yr, 0.56 ERA, 13.5 K/9, 3.9 BB/9, 4.5 H/9 in AA)

Hyped Dominators

No one was ever denying that Buehler or Syndergaard would be monsters from the get-go. They both had ridiculous stuff and even though Syndergaard struggled with a 4.60 ERA in the minors the year before, he finally flipped the switch before getting a mid-season call-up with the Mets and proceeding to obliterate MLB hitters too. You will never find a young pitcher who struggled in the minors turn things around as soon as he starts facing hitters who are 20-50% better than they’ve been facing. Stuff always shows up in the numbers, and primarily in K/9 rather. In fact, you might as well ignore BB/9 all together, as that is a teachable skill. You can’t teach triple-digits with two plus breaking balls.

Surging Dominators

The interesting cases here are with older pitchers who were never all that hyped as prospects but suddenly surged forward within a calendar year of their MLB debut. Everyone remembers Corey Kluber, Jacob deGrom, Mike Clevinger and Dallas Keuchel as similar stories but more recently, it has been McCullers, Castillo, Lamet and Paddack who went from B- prospects to looking like aces overnight. Sometimes pitchers just figure something out and when it happens, it happens overnight and you’d better not chalk it up as a fluke. Check the past 80 innings. If he has dominated throughout, you can bet your bottom dollar, the stuff is here to stay and the rookie pitcher is the real deal.

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