OPS and the Defensive Spectrum

Baseball observers often make the mistake of comparing players by using their offensive statistics without taking into consideration the position they play. For instance, in the 1970's when major league shortstops hit like dime-store clerks a shortstop like Roy Smalley was very valuable offensively. While his 1978, 1979 and 1980 OPS+ totals of 122, 110 and 104 are just a bit above average when viewed against the league in its entirety, in actuality he was a much more valuable player offensivelt when compared against his shortstop counterparts. Since shortstops of that era hit far below the overall league average OPS, his above average figures against the overall league average became even more impressive when compared against other shortstops.

Such insights accentuate the extreme offensive value that catcher Ivan Rodriguez has given his teams over his career. With the catcher position ranging between 8 and 11 runs below average for much of Rodriguez's career, his career 112 OPS+ against the league average is more positively accentuated when compared to the other catchers of his era. Instead of being merely an above average hitter over the course of his career, Rodriguez can be viewed as a very valuable offensive commodity when compared against the others who played his position. This distinction increased his overall value and highlights the unique opportunity given to a team by a player who hits significantly better than the others who play his position.

An additional note of interest. From David Gassko's article comes this conjecture on the evolution of the catcher position from the late 19th century and into the early 20th century.

In the early days of baseball, catchers were absolutely awful hitters—on average, -14 runs per 162 games. That’s to be expected, as bunts were very common during these years and so a catcher’s defense was very important. Also, as pitchers began to throw overhand and batter-friendly rules disappeared from the game, catching pitches itself became more difficult and thus restricted the position to relatively good fielders.

As more players became accustomed to catching and bunting became less prevalent, catcher offense slowly improved. The average catcher between 1914 and 1986 was -5 runs per 162 games—still below-average but not that bad.