25 & Under Rankings (2020): Top 5 First Basemen: 2 Prospects & Significant Surprise Fill Out List


Who are the next wave of superstars in Major League Baseball? That’s what we are about to dive into, as we go position-by-position, looking for the best players who are 25-years old or younger (as of April 1, 2020). Obviously, things will be slightly skewed to those who have already reached the Majors and produced, but minor leaguers and their upside will not be ignored.

Earlier this week we kicked off these rankings by looking at the Top 5 Catchers (click here to view), so now let’s move on to first base:

1) Cody Bellinger – Los Angeles Dodgers
Age – 24

It was a monster breakout for Bellinger in 2019, as he hit .305 with 47 HR, 115 RBI, 121 R and 15 SB.  However there was a distinct split in his production, which can’t simply be ignored:

  • First Half – .336, 30 HR, 71 RBI, 70 R
  • Second Half – .261, 17 HR, 44 RBI, 51 R

Obviously no one is complaining about the second half production, but long-term what can we expect?  The key difference was in the power, obviously, and luck.  He appeared to become more focused on home runs in the second half (fly ball rate jumped from 40.3% to 45.2%) yet his HR/FB dropped (28.3% to 20.0%) and his BABIP in turn tumbled (.328 to .266).

He also started to see fewer and fewer hard pitches, which could also explain the drop in production.  Again it’s not to say that there’s any reason for concern, it’s just that he simply could be closer to the second half production than the first.

2) Pete Alonso – New York Mets
Age – 25

Alonso set the rookie home run record in 2019, slugging 53 HR to go along with 120 RBI and 103 R.  Obviously it’s impossible to expect him to replicate those types of numbers, it’s clear that he’s quickly emerging as an elite source of power.  The question is whether or not he can make the adjustments and maintain at least a .260ish average, as we saw a significant regression as the year progressed:

  • First Half – .280
  • Second Half – .235

That said, there wasn’t a huge change in his approach in terms of his power focus that should’ve justified the drop in his BABIP (.298 to .258).  While strikeouts are going to be part of his game, his “worst” Whiff% was 18.89% against off-speed pitches.  With more experience he should be able to settle in with a decent strikeout rate (24.5% in the first half) and with better luck .260+ is believable.

He may not be Bellinger, but a .260/40/110 type player?  It’s hard not to love him moving forward.

3) Andrew Vaughn – Chicago White Sox
Age – 22

The third overall selection in 2019, Vaughn instantly becomes an intriguing name to watch.  There is no questioning the power potential he brings, but his 9.3% SwStr% across three levels in his first taste of professional baseball is also promising.  If he can bring a blend of power and approach, we could be talking about an elite option at the position.  Maybe we should limit his ranking due to lack of experience, but after the top two names it’s hard to argue against Vaughn having the most upside of anyone at the position.

Just look at this scouting report regarding his swing, courtesy of MLB.com, and it’s hard not to get extremely excited:

“Vaughn keeps things simple at the plate, allowing his natural hitting ability and natural power to take over rather than trying to do too much. He has a pretty right-handed swing with no holes as well as considerable bat speed and strength. With his all-fields approach and refusal to chase pitches out of the strike zone, he projects as a .300 hitter with 30 homers and 80 walks on an annual basis.”

4) Nate Lowe – Tampa Bay Rays
Age – 24

If Lowe were playing for a team that was guaranteeing him full-time AB he would be higher on people’s radars.  However he plays for the Rays, who love to try and play matchups and before things were shutdown he was primed to battle for 1B/DH at bats with Ji-Man Choi, Jose Martinez, Joey Wendle and a host of others.  However Lowe had a strong showing at Triple-A last season, despite taking a step backwards when given an opportunity in the Majors:

  • Triple-A – .289 (95-329), 16 HR, 63 RBI, 63 R
  • Majors – .263 (40-152), 7 HR, 19 RBI, 24 R

They key is his approach, and even in the Majors he showed it (10.6% SwStr%, 30.0% O-Swing%).  He also proved willing to use the entire field (28.8% Oppo%) and ability to hit the ball hard (41.3% Hard%), while his statcast numbers also scream of better production (he was above average in Barrel%, Exit Velocity and Launch Angle).

He has breakout sleeper written all over him, and don’t be surprised if he emerges when/if the opportunity comes. For more on Lowe, click here to view our full report.

5) Triston Casas – Boston Red Sox
Age – 20

There are a few names that were considered for this spot, including someone who is a potential future teammate.  However Michael Chavis’ issues with his strikeouts (18.6% SwStr%) and regression in his luck metrics (.347 BABIP despite a 33.6% Hard%) left him short of making the list.  Instead it’s Casas, who we graded as a “B+” prospect and showed signs of being on the verge of a monster breakout in 2019.  Just look at what we said about him:

“The 2018 first round draft pick got his first real time of professional baseball, after injuries limited him to 4 AB in 2018.  There’s no questioning his power potential and ability to draw walks, the question will be if the 20-year old will be able to make enough contact to tap into it.  Playing most of the season at Single-A, he showed signs of improving his strikeout rate as the season progressed:

  • First Half – 26.44%
  • Second Half – 20.26%

That type of improvement shows his significant upside, because if he can maintain the improved rate with the other skills he has difference-making potential.  While he’s at least a year away, he has the potential to put it all together and start moving quickly through Boston’s system.”

Also Considered – Evan White (SEA), Michael Chavis (BOS)

Note – Matt Olson turned 26-years old on March 29, therefore we left him off the list.  Had he been included, he could’ve pushed Pete Alonso for the #2 spot.

Sources – Fangraphs, Baseball Savant, Brooks Baseball

Make sure to check out all of our 2020 prospect rankings:

AL EastAL CentralAL West
Baltimore OriolesChicago White SoxHouston Astros
Boston Red SoxCleveland IndiansLos Angeles Angels
New York YankeesDetroit TigersOakland A's
Tampa Bay RaysKansas City RoyalsSeattle Mariners
Toronto Blue JaysMinnesota TwinsTexas Rangers
NL EastNL CentralNL West
Atlanta BravesChicago CubsArizona Diamondbacks
Miami MarlinsCincinnati RedsColorado Rockies
New York MetsMilwaukee BrewersLos Angeles Dodgers
Philadelphia PhilliesPittsburgh PiratesSan Diego Padres
Washington NationalsSt. Louis CardinalsSan Francisco Giants
PositionLast Updated
First Baseman--
Second Baseman04/15/20
Third Baseman04/20/20


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