David Ortiz and the devaluation of traditional statistics

Last night’s blast to right field was David Ortiz‘s 30th home run of the season, the eighth time that Big Papi has reached that mark in his twelve seasons with the Red Sox. Those 30 bombs rank fourth in Major League Baseball and Ortiz also leads the league with 93 RBIs this season. On the surface, it doesn’t look like Ortiz is slowing down even at the ripe age of 38 years old; even in a season that has seen Ortiz remain at or near the top of the league in power numbers, however, advanced statistics show red flags over Big Papi’s 2014 performance.

The first of those red flags come from a stat that isn’t very advanced at all: batting average. While Ortiz’s power has been as prevalent as ever this season, his batting average has slipped to .263 this season, a steep drop from last season’s .309 mark and his career .285 average. While that fall is due in part to an unusually low .252 BABIP (batting average on balls in play), a good tool for measuring how lucky a player has gotten, we can’t exclusively attribute his drop in batting average to bad luck at the plate.

The primary factor for Ortiz’s drop in batting average is his decrease in line drives and corresponding uptick in fly balls. His line drive rate has fallen from 22.6% last season to 18.0% in 2014 while his fly ball rate has risen sharply from 38.7% to 46.3% in those two seasons. That increase in fly balls explains why his power numbers have remained strong, as his home run per fly ball rate has stayed roughly the same (17.9% last season and 17.6% this year), but why his batting average has fallen as line drives result in most non-home run hits.

The question which surrounds Ortiz is whether his 2014 performance represents the new Big Papi and if his next few seasons will echo his 2014 results. Will Ortiz’s power remain excellent for a few more seasons while his batting average and on-base percentage sink with age?

It’s hard to say that this is the beginning of a trend and not just an aberration given that this is the first year that Ortiz has displayed these tendencies. However, given his age, it’s more than likely that this is the beginning of his decline and it would be unfair to expect a major turnaround in his age 39 season. Plus, while Ortiz hasn’t been bad by any means this season– his .263/.355/.523 slash line is by far the best on the Red Sox– his impressive traditional power numbers like RBI, home runs, and even slugging percentage don’t tell the whole story this year.

We all knew that Ortiz was bound to decline eventually and, if this is the rate at which he’s slowing down, then we can all live with that. Ortiz is still having a great season offensively and still should be able to effectively slot into the middle of the Red Sox lineup for at least the next year or two. However, this season is the first evidence of a decline by Ortiz even with his league leading 93 RBIs and 30 home runs.