Derek Jeter’s Dimming Star

Ladies and gentleman: ready your pitchforks. Light your torches. Today, I am going to commit baseball sacrilege. I come not to bury the Yankee Captain, but I must point out that in many respects, Derek Jeter’s 2008 campaign was the worst of his career.

This past season, Jeter posted just a 0.26 WPA/LI, the lowest full-season mark of his distinguished career and a middling 8th among 17 qualified shortstops. Jeter’s .408 slugging percentage, .107 Isolated Power (ISO) and .343 wOBA were also career lows.

Since an outstanding 2006 season (.343/.417/.483), Jeter’s production has taken a sizeable hit in each of the past two years. Using the same formula to convert wOBA into runs above average that we employed while examining Miguel Cabrera, it becomes apparent that the 1992 first-rounder has been hemorrhaging offensive value:

2006

Jeter’s wOBA: .399
AL LG wOBA: .339

37.3 Runs Above Average

2007

Jeter’s wOBA: .369
AL LG wOBA: .338

19.25 Runs Above Average

2008

Jeter’s wOBA: .343
AL LG wOBA: .335

4.65 Runs Above Average

Granted, 2006 was one of Jeter’s better seasons with the bat, but he has lost over three wins of offensive value since that point.

While Jeter has shown pretty solid pop for a shortstop in his career (.458 SLG, .142 ISO), he has often put the ball on the grass. His groundball percentage has hovered between 56.1% and 60% over the past four seasons, and sits at 55.6% for his career. With pretty solid speed and a line-drive bat (career 20.8 LD%), Jeter has consistently posted high Batting Average On Balls in Play (BABIP) marks (.361 career). However, it seems as though those skills might be in the process of eroding. Jeter’s 17.9 LD% in 2008 was the lowest mark that Fan Graphs has going back to 2002, and his .336 BABIP was the second-lowest of his career.

While it’s possible that his BABIP drop was just a blip, it seems pretty unlikely. Our own Peter Bendix recently co-authored a study on Expected BABIP at The Hardball Times, which introduced a more comprehensive and accurate way of measuring XBABIP for hitters. Among the facets of a player’s game that bode well for XBABIP are batting eye, line drive percentage, speed score and pitches per plate appearance. His batting eye (0.61 BB/K) was essentially unchanged (0.59 career) and his 3.7 P/PA was normal, but Jeter has shown significant erosion in the other two categories As mentioned before, Jeter’s 2008 LD% was his lowest mark by a decent margin, and it appears as though the captain’s wheels are grinding to a halt.

Using Bill James’ Speed Score, we can get a better read on Jeter’s speed (or lack thereof) in recent seasons. Speed Score is found by calculating a player’s score in five categories: stolen base percentage, stolen base attempts, triples, runs scored per times on base and number of times grounded into a double play. By adding all five categories up and dividing by five, you get the player’s Speed Score. Speed Scores range from 0-10, with the average player posting a number in the range of five. If you want the full details on the formula used, take a look here.

Here are Jeter’s Speed Scores over the past three seasons…

2006

SB%: 8.09
SB Attempts: 5.77
Triples: 2.96
Runs: 7.62
GDP: 5.87

Total Speed Score: 6.06

2007

SB%: 4
SB Attempts: 4.61
Triples: 3.08
Runs: 7.03
GDP: 3.03

Total Speed Score: 4.49

2008

SB%: 4.17
SB Attempts: 4.03
Triples: 3
Runs: 6.62
GDP: 1.4

Total Speed Score: 3.84

Since 2006, Jeter has gone from possessing above-average speed to posting a Speed Score more commensurate with a first base/DH type. Another Bill James stat, Base Running Net Gain, also showcases Jeter’s slowing game. Base Running Net Gain compares a player to the league average in: advancing from first base to third base, second to home, first to home, ground into double play percentage, and stolen base percentage. A swift runner for most of his career (with a net base running gain of +76), Jeter is now below-average:

2006: +24 Net Bases
2007: +9 Net Bases
2008: -13 Net Bases

Not surprisingly, Jeter’s XBABIP under Peter’s system has fallen each year as well: .339 in ’06, .332 in ’07 and .310 this past season. With a three-year decline in LD% and rapidly deteriorating speed, Jeter’s BABIP drop looks like a significant trend, not just an anomaly. Posting a GB% near sixty was okay for the lithe, peak-career version of Derek Jeter, who possessed the athleticism to beat out fielders and reach base on infield hits. However, it’s a much less viable strategy for the current, decline-phase Jeter, who appears to be squarely in the clutches of father time.

I realize that criticizing Jeter is sort of the baseball equivalent of bashing Santa Claus, but there are undeniably a number of concerning trends here. A five year decline in ISO..a three year decline in LD%…a high GB% without the requisite speed to make those worm-burners count. I don’t really see a “flotation device”, a skill to fall back on. It sounds downright odd to say, but you might just want to avoid that Jeter guy on draft day.