Out of the nearly 1700 players who have appeared for the Red Sox through the 2013 season, there have been almost 800 players that have worn a Boston uniform for just a single season. Some may be remembered for one fleeting moment in the spotlight, like Billy Rohr, who was one out away from a no-hitter against the New York Yankees in his first major league start in 1967 but made just eight more starts that season and won only one other game (his next start, also against the Yankees). Others may have been aging former All-Stars looking for one last season under the sun, like Carlos Baerga or Mark Lemke.
Then there are those who use that one season to showcase their talents, performing at a level perhaps unexpected. Every plate appearance seems to produce, every play in the field seems fluid and flawless, and the sportswriters and fans watch in awe and amazement.
To compile this list, we considered positional players — pitchers will be examined in a later post — with a minimum of 500 PA and only one season played between 2001 and 2012; we discounted 2013 players since a percentage of them may return this season. All statistics are compiled from Baseball-Reference.com.
Top Single Season OPS+
Top Single Season WAR
Top Single Season Offensive WAR
Top Single Season Defensive WAR
Clearly, Adrian Beltre walks away with the title of having the best single season performance by a position player in team history. His 141 OPS+ and his WAR of 7.8 place him at the top of each list shown here, and what is further impressive is that his dWAR of 2.4 made him valuable on both sides of the ball, whether he was holding a bat or wearing his third baseman’s glove. Beltre has continue to showcase those talents since leaving Boston for the Texas Rangers as a free agent after the 2010 season, with an average OPS+ of 136 and a total WAR of 18.2, though his dWAR has steadily declined as he has reached his mid-30s.
Nick Esasky is another player of note who, while lacking defensively (his dWAR in 1989 was -0.6, primarily as a first baseman), finished with an above-average OPS+ of 133 and a WAR of 3.9 in what proved to be his best statistical season. Unfortunately, after signing a substantial free agent contract with the Atlanta Braves, Esasky played just nine more games in his career due to vertigo stemming from an ear infection, which forced him to retire from baseball at the age of 30.