Different Scales, Same Results

Slugging percentages and on base percentages are the two key figures to measuring a player's contribution at bat. They are however, measured on somewhat different scales -- for example in 2007, the NL's overall league slugging percentage was .423, while the overall league on base percentage was .334. That's one reason why adding them together in the statistic known as OPS (on base plus slugging) probably slightly overvalues hitters with high slugging percentages and slightly undervalues hitters with high on-base percentages (nevertheless, I still find OPS enormously useful, as it is really only slightly off as an estimate of a player's hitting value in most cases and it is really easy and convenient to use). In any event, the result of the two different scales is that it is relatively unusual for one player to have OBP and SLG figures that are very close to one another. Such a confluence only happens with players with a unusual combination of skills -- a relatively high capacity for getting on base given the player's power production.

The Mets' Luis Castillo is such a player of unusually close OBP and SLG figures; he is quite good at getting on base but not good at all on the power side. In 2007, Castillo had 199 at-bats for the Mets after joining the team from Minnesota at the end of July. His OBP in his time with the Mets was .371 and his SLG .372, a difference of only .001. Only four other players have had Mets seasons with at least 100 ABs in which their SLG and OPS were separated by no more than .001:
1974 Wayne Garrett, 522 ABs, .337 OBP and .337 SLG
1977 Doug Flynn, 282 ABs, .220 OBP and .220 SLG
1997 Rey Ordonez, 356 ABs, .255 OBP and .256 SLG
1999 Luis Lopez, 104 ABs. .308 OBP and .308 SLG

Flynn and Ordonez were so horrible on offense generally that the sort of hit rock bottom on both elements. Flynn's 1977 season for the Mets, after coming over in June from the Reds as part of the Tome Seaver trade, may have been the worst batting season in the history of the team, considering how many ABs he was given despite his futility. Ordonez' 1997 wasn't much better. In contrast, Wayne Garrett's 1974, like Castillo's 2007 with the Mets, wasn't bad from an offensive point of view, especially as we are talking about middle infielders here. Though Garrett's '74 OPS was much lower than Castillo's NL '07, Garrett was hitting in a much lower run scoring environment.