Maxx Wayne: Slump, Surge or Stable? 2020 Sophomores

This article is by guest author Maxx Wayne

The 2019 MLB season brought a vast supply of young, energizing talent to the game of baseball. In a rookie class highlighted by the number 1 and 2 prospects in baseball, two sons following in the footsteps of their fathers: Vladimir Guerrero Jr. and Fernando Tatis Jr. the Rookie of the Year awards went to two undervalued slugging prospects in Pete Alonso and Yordan Alvarez. The 2019 rookie class was extremely deep with some players producing for their big league clubs from opening day through game 162.

In 2019 we saw multiple Sophomores thrive, such as Juan Soto, Gleyber Torres, Ronald Acuna Jr. and Jeff McNeil. Others hit somewhat of a lull, such as Harrison Bader, Jesse Winker and Nick Martini. Most successful rookies continue to improve in their second season, but it is never a guarantee.

I am going to investigate a handful of highly touted 2019 rookies. What can we expect from 2020 Sophomores? Who will have a “Sophomore Slump” and who will be a “Sophomore Star?”

Vladimir Guerrero Jr.

Vlad Jr. came into the 2019 season with more hype than any other rookie in recent memory. This is partly due to being the son of Hall of Famer and partly due to being the #1 prospect in the game. He became a household name after his historic showdown at the 2019 Home Run Derby against Pete Alonso and Joc Pederson. Most people felt Vlad underperformed, but it is not easy for a 19-year-old to produce at the highest level of baseball in the world. Let’s look at some of his statistics throughout his professional baseball career:


Vlad clearly had the worst year of his professional baseball career, but that can be expected for a rookie thrust into the big leagues in his teens. He had a substantial decline in wOBA which can be concerning, but his wRC+ was just over 100, meaning he was right around a league average hitter. It was unrealistic for him to maintain his BB/K rate in MLB, but he still kept it above average in his rookie season.

Based on the data, here is what I am expecting out of the Blue Jays’ third baseman for the 2020 season: More quality plate appearances by becoming more patient at the plate. I expect his BB% and LD% to increase the most. His LD% and BB% are most likely correlated due to his confidence at the plate. This confidence is boosted from his above-average launch angle and exit velocity. Launch angle and exit velocity have become huge points of emphasis in modern-day baseball because they correlate with more home runs. Vlad Jr.’s high launch angle and exit velocity have led to increased confidence at the dish, which leads to more line drives. Throughout his minor league career, the more line drives he was hitting, the more he was walking. Vlad will increase his LD% which in turn will lead to more walks and a higher wOBA. Vlad should have a big increase in production in 2020, leading to around a 120 wRC+. Expect big things from one of the most exciting young players in the game today.

Fernando Tatis Jr.

File:Fernando Tatis Jr (36141794371).jpg
Cred. Marshall Dunlap

Fernando Tatis Jr. or El Nino, has cemented himself as one of the most thrilling players in the major leagues even after playing only 84 games. Tatis was electric, demonstrating impressive hitting skills and showcasing near impossible plays on defence. The biggest concern over San Diego’s shortstop is his capability to stay on the field. His past two seasons have been cut short due to injury. This may be due to the team being cautious with a young star but should this be setting off alarms, is it a sign of injury proneness? Regardless of that, let’s try to decipher whether he will be able to continue his success:

The first thing that jumps out is a .410 BABIP in 2019. This is something that will surely decline in 2020 for Tatis, which means his wOBA and wRC+ will decline too. Also, his 31.9% HR/FB is by far the highest for his career. Now, this could be due to the new “juiced balls,” but nonetheless it is sure to decline in 2020. His K% has been concerning throughout his professional career, so I expect this to stay around 26-31%. Another stat to point out is throwing errors. Tatis had 14 throwing errors and -13 outs above average (OAA), only Jorge Polanco had a worse OAA last season. This is most likely because Tatis has one of the strongest arms at the shortstop position. That can lead to him being overconfident, which likely led to the 14 throwing errors. These numbers should gradually improve throughout Tatis’ career, so I do not consider this an area of concern. Overall, I expect somewhat of a decline in El Nino’s production in 2020, rooted in fewer HRs and a lower BABIP.

Bryan Reynolds

One of the biggest surprises in the 2019 rookie class was Pirates’ Bryan Reynolds. He finished 4th in NL Rookie of the Year voting behind Pete Alonso, Mike Soroka and Fernando Tatis Jr. He also finished among the top 10 in MLB for batting average. Will Reynolds build on this performance? Let’s take a look at his professional stats:

Reynolds did have a great rookie season and it does not seem too out of character for him. His wOBA and wRC+ seem to be in line with his typical performance. Also, you can expect a rookie to have a decline in walks and line-drive % when he enters the league, but that was not the case with Reynolds. This could be due to Reynolds’ mature plate approach, which causes him to take confident, calculated swings at the plate. He had a 37.5% sweet spot %, second highest among rookies. One thing that should decline in 2020 is his HR/FB rate because he nearly doubled his career-best in low A from 2016. I expect Reynolds to hit fewer home runs this season, but maintain a high BABIP which will allow him to retain an elevated wOBA. Reynolds’ slugging percentage may decline, but I expect improvement in his overall hitting for 2020.

Pete Alonso

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Cred. David B. King

Pete Alonso broke out onto the MLB scene with the most home runs in the entire league and he did it as a rookie. The last player to accomplish that feat was Mark McGwire in 1987 when he tied Andre Dawson with 49 home runs. Only one other player has done this before, Tim Jordan of the Brooklyn Dodgers, when he hit 12 home runs in 1906.

This is quite an impressive feat for a player just starting his career, but it raises the question as to whether Alonso will be able to do it again in 2020. Even McGwire dipped to 32 home runs in his sophomore year. Hitting the most home runs in MLB in consecutive seasons has only happened a handful of times in the live ball era. Jimmie Foxx, Ted Williams and Ralph Kiner all hit the most HRs in the league for 6 consecutive seasons (the record) and seven other players have achieved the feat of most HRs in MLB in any number of consecutive seasons. Will Alonso join this exclusive list?

Alonso has had a consistent start to his professional baseball career. What inconsistency does exist comes from his K%, but that is expected to increase as a player advances to higher levels of baseball. He has had a consistent increase in HR/FB throughout his career, which is a positive looking forward to 2020. Alonso does not ground into a lot of double plays for a first baseman. Also, a BABIP of .280 is low for a hitter that had a season like the Mets’ first baseman. Alonso was tied for second in the league with 66 barreled balls in 2019.

What I expect in 2020 from the Polar Bear is somewhat of a similar season or possibly a better one if his BABIP increases. Since the 2020 MLB season will certainly be shortened, he will not hit 50+ home runs again, but Alonso would be my bet to win the MLB home run title again. If Alonso can reduce his K% and repeat his success with a similar wOBA, he will be a favourite to win the 2020 NL MVP.

Yordan Alvarez

Yordan Alvarez began his MLB career with a home run in his first game on June 9. He then proceeded to smack 27 long balls in only 87 games. This led to him winning the AL Rookie of the Year award. Yordan is known for his ability to hit for power and contact from the left side of the plate. He surpassed his 2019 expectations, but will he be able to build on that in 2020?

Yordan has been somewhat consistent throughout his MLB career. This consistency is mostly shown through his BB%, where it dipped below 10% once. It is surprising to not see a decline in Yordan’s positive stats or an increase in K% for his first MLB season. His BABIP was high, but not to an extent where it leads me to believe he got “lucky” in his rookie year. A 14.1% BB% is exceptional for a rookie, which leads me to believe his success will continue in 2020. Also, most players saw an increase in HR/FB in 2019 due to the “juiced balls,” but Yordan did not see much of an increase; therefore, we may see an increase in HR rate for Yordan in 2020. He also ranked in the top 15 for hard hit ball % with 48.9% and among the top 10 in barreled balls/PA with .103.

One of the main critiques of Yordan is he cannot hit lefties very well, so let’s look at his RHP/LHP splits in his rookie year.

This stat line should put to rest the idea that Yordan Alvarez cannot hit lefties. His wOBA is very similar against both lefties and righties. He does walk a lot more against RHPs, but that is logical because those pitchers will typically pitch around him more. Something that catches the eye is Yordan has a lower K% and better HR/FB.

In 2020, expect Yordan Alvarez to continue his dominance at the plate and to continue to torment all pitchers. There is not much, if any, weakness in Yordan’s bat, and he should continue to be an elite hitter throughout his career.

Eloy Jimenez

Eloy had a solid rookie season at the plate. He was just about right where most people expected him to be. He’s a slugger that can hit for contact. He finished 4th in AL Rookie of the Year voting with 1.9 fWar. An interesting player because he was traded between Chicago farm systems in the Jose Quintana trade. For now, that seems to be a good trade for both sides, but let’s take a look at Eloy’s stats throughout his career to see how that might change:

The first thing that jumps out at me is his big increase in K% in the MLB. This may be concerning at first, but it is expected to happen, so I do not feel it is an area of significant concern. What is more alarming is how low his walk rate has been throughout his professional career. With a BABIP of .308, there is clear room for improvement in Eloy’s batting stats. The decline in LD% in 2019, relative to the rest of his professional baseball career, gives room for improvement in 2020. Although, he ranked 19th in MLB in hard-hit ball % with 47.9%. His GIDP/AB has been slightly high throughout his professional career, but I am not concerned so long as he achieves more lift and his LD% improves in 2020. Eloy has been consistent throughout his professional career and I expect that to continue in 2020. Expect a season with better contact hitting and fewer strikeouts from Eloy Jimenez.

Keston Hiura

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Cred. Ian D’Andrea

Keston Hiura was the Milwaukee Brewers #1 prospect. His MLB season started a little slow, but he picked it up and finished with a strong rookie campaign. Hiura split time at second and third base, but the Brewers infield was shaken up this offseason after losing Mike Moustakas to the Reds and trading for Luis Urias, former top 30 prospect, then of the San Diego Padres. Hiura will most likely spend more time at third base this season. Let’s take a look at his hitting statistics throughout his professional baseball career:

It is hard to ignore a 30.7% K%, even for a rookie. This is concerning because you cannot necessarily say his K% is so high merely because he was a rookie. He has been plagued by an above average K% throughout his pro career. Another warning sign is his .402 BABIP. This will most likely decrease in 2020, in fact, .402 could be his highest BABIP of his MLB career. Hiura didn’t provide enough power to offset his lofty K% and insufficient BB%. These are all concerning to me and suggest Hiura may have a sophomore slump in 2020. There are a lot of holes in Hiura’s stat lines, which leaves me pessimistic about his MLB career.

Nick Senzel

Senzel came into the 2019 season as the #1 prospect in the Cincinnati Reds farm system. He is the definition of a utility player spending time at second, third and all outfield positions. This is a clear plus, value Senzel could bring to any team, but to make it in modern MLB you have to be able to hit. Here are some of his batting stats throughout his professional baseball career:

Senzel had a down year in 2019 as a rookie, but there are some positives. His 24% LD% is something that I expect him to build on in 2020. He did have a low wOBA with a higher than expected K%, but these are the lows of his professional career. This gives me hope that he will slowly improve, starting in 2020. He will not hit many more HRs, but he will reach base more, leading to a higher BB% and BABIP. While Senzel may have been one of the more disappointing rookies of 2019 expect a better 2020. Even if he doesn’t diverge too far from his 2019 numbers, perhaps landing with a wRC+ of around a 100.


As a recap, there were a lot of impressive rookies in 2019, but not all of them will be able to maintain their 2019 performance in 2020. After analyzing the stat lines of these 8 2019 rookies, I made predictions about how they would play in 2020. I decided to divide them into three groups: Surge, Stable, and Slump. Surge players will be the players that I expect to improve on their 2019 seasons. The group of stable rookies will be the players I expect to have similar seasons in 2020 to 2019. The slump group will be the players I expect to have a “Sophomore Slump” season and decrease their production in 2020.

  • Surge: Vlad Guerrero Jr. and Eloy Jimenez
  • Stable: Bryan Reynolds, Pete Alonso, Yordan Alvarez, and Nick Senzel
  • Slump: Fernando Tatis Jr. and Keston Hiura

It will be interesting to see if these rookies will rise to the occasion in their Sophomore season or if they will fall to the “Sophomore Slump” curse. All the players I analyzed are great athletes and will most likely have long MLB careers, but not all of them will have smooth journeys.