In 2012, Bryce Harper was the Rookie of the Year and an All-Star in his first season in MLB, having collected all of 536 plate appearances in the minor leagues before getting his final call to Washington. After a season of tremendous hype, production, and accolades, how can Bryce Harper follow-up?
It is impossible to predict future results in MLB.
No one could predict the injury that Conigliaro suffered. No one could predict Mel Ott hitting 42 home runs in his second full season (1929), Al Kaline hitting .340 in his second full season (1955), or Ty Cobb hitting .350 in his second full season (1907) based on their age-19 seasons above.
George Davis, whose 1890 season was not very statistically aligned with Harper’s 2012 season due to a lack of power in the dead-ball era, has the greatest Similarity Score, 930, at Baseball Reference, when comparing Harper’s rookie season to any other 19-year-old in MLB history. Mel Ott was second, 928, and his second full season would mean that Harper is about to explode, as Ott posted a .328/.449/.635 with the aforementioned 42 home runs and a whopping 151 RBI for the New York Giants. However, using Similarity Scores for statistics alone and not factoring in age, Harper’s 2012 season was most similar to Bill Howerton, a career .274/.364/.472 hitter over all of four seasons in the majors.
No one could predict the injury that Conigliaro suffered. No one could predict Mel Ott hitting 42 home runs in his second full season (1929), Al Kaline hitting .340 in his second full season (1955), or Ty Cobb hitting .350 in his second full season (1907) based on their age-19 seasons above. There is no perfect way to determine how great a player will become, but player values are determined through WAR. So, based on their age-19 seasons:
|Name||Season||Fangraphs WAR||Baseball Reference WAR|
|Ken Griffey, Jr.||1989||2.8||2.9|
If WAR is truly the greatest way to explain overall player values, then Harper had the best season of any 19-year-old in the history of baseball, and if the careers of any of the players named along with him in this article are an sign of where he may end up, then Bryce Harper is well on his way to becoming one of the greatest players in the history of MLB.