Fangraphs, for example, lays it out in an easier to understand way.
Martinez played a lot of 3rd in 1991. He was credited with 6 fielding runs above average. He gets a positional adjustment of 1.1 (based on the position and the playing time) and totals 7.1 runs above average.
In 2003 he only played DH. He gets 0 fielding runs above average. The positional adjustment was -15 and he totals -15 fielding runs above average for the season.
12/5/2013 4:59 PM (edited)