Analytics Stories

CHAPTER 14Was Derek Jeter a Great Fielder?

I'm not a Yankees fan, but like all baseball fans, I appreciated the greatness of Derek Jeter. He received 396 of 397 possible votes (only Yankee reliever Mariano Rivera was unanimous) in the 2020 Hall of Fame vote (the first year he was eligible). The Gold Glove is given each year in baseball to the best fielder at a given position. Jeter won the Gold Glove for shortstops five times: 2004–2006 and 2009–2010. (Only four shortstops won more Gold Gloves.) Unfortunately, these Gold Gloves were a miscarriage of justice, based primarily on a lack of understanding of what makes a good fielder (see grantland.com/features/the-tragedy-derek-jeter-defense/). In this chapter, we will show that Jeter did not deserve his Gold Gloves. The moral of the chapter is that bad metrics can lead to improper evaluation of your employees.

Fielding Statistics: The First Hundred Years

The first Major League Baseball game was played in 1869. Until sabermetric genius Bill James came up with range factor in the 1970s, the most commonly used fielding statistic was fielding percentage, which is calculated by the formula Putouts + Assists divided by Putouts + Assists + Errors. Essentially, it is the fraction of balls that a fielder “handles” successfully. Table 14.1 shows Jeter's and the American league average (per Baseball-reference.com) fielding percentages during his Gold Glove years. For example, in 2009, Jeter successfully fielded 98.6% of balls he handled, ...