Does the Sophomore Slump Really Exist?

Abstract

INTRODUCTIONSports players, analysts, and fans alike have long acknowledged the decline in performance that commonly occurs between the first and second years of players' careers. This phenomenon, nicknamed the sophomore slump, most often refers to former first-year standouts plagued with comparatively poor second-year performances.1Analyses tend give the most attention to the sophomore slump when it affects those who received the Rookie of the Year (ROTY) award. Bennett describes the ROTY award as a Most Valuable Player Award, limited to eligible players.2 First officially given in 1947, the award honors a single rookie player (1947 and 1948) or a rookie player from the American League and a rookie player from the National League (1949 until present). Ex-post facto ROTY award winners between the years of 1872 and 1948, until each league began identifying its own ROTY, have also been named.3The contention about the relationship between the ROTY award and the sophomore slump suggests that those who have won the award may be average players who just happened to have good seasons during their first years in the major leagues. Sabermetricians have, to varying degrees, addressed this possibility before. In a discussion of his recent research regarding ROTY award recipients, Bennett implies a bit of arbitrariness to qualifying for the award, as it focuses upon a player's single-year performance with no baseline (no pun intended) by which to judge his overall performance.4 He specifically presents the sophomore slump as an aftermath of having received the award. Other studies on the matter focus upon the heightened attention to the sophomore slump for ROTY award recipients.5 Taylor and Cuave also discuss the sophomore slump in relation to players with exceptional rookie-year performance.6 Although they never specifically identify ROTY winners as the only players affected, they note that 80 percent of those who received the ROTY award between 2000 and 2003 performed more poorly during their second years in the major leagues than they did during the first. Taylor and Cuave also examined average productivity for all players receiving votes for the ROTY between 1994 and 2003, finding a 12 percent decrease between their freshman and sophomore years.Finding examples of particular Rookie of the Year award winners who have declined in performance during their second years in the major leagues provides little challenge. Consider the following.7* After a standout first season in the Major Leagues and receiving the 2002 American League ROTY award Eric Hinske's second season was plagued by injuries and a 20 percent decline in Win Shares (WS).* The WS of 1976 American League ROTY, Mark Fidrych, also dropped 20 points by the end of his second years playing Major League Baseball.* Angel Berroa, the 2003 American League ROTY, saw a 13-point drop in his On-Base Percentage Plus Slugging (OBP+) and a 6 point drop in his WS numbers between his first and second years in the Major Leagues. Berroa's performance declined so much that his team relegated him to the Minor Leagues for a portion of his second season.* Statistics for Berroa's National League counterpart, Dontrelle Willis, also indicate a decline in performance just after he received the ROTY award. Specifically, his sophomore-year Earned Run Average (ERA) exceeded his freshman-year ERA by .72 and his WS for his sophomore year fell 4 points shy of that for his freshman year in the Major Leagues.These examples only begin this list of ROTY players with worse performances during their second than during their first years in the Major Leagues. Others have had similar, although not necessarily so dramatic, experiences. Walters and Gleeman, for example, mention many of these players in their articles.8 The repeated mention of having received the ROTY award and experiencing a sophomore slump in conjunction with one another clearly suggests a connection between the two. …