Yankees shortstop Derek Jeter has never been a mitt-wielding maestro, and, with his offensive production dropping, his poor defense has become an increasing liability.

A new plus/minus rating in Bill James’ Handbook rates Jeter the worst shortstop in MLB for the past three seasons.  In 2007 and 2008, his glove alone cost the Yankees 30 runs.  The only gaps he appears to be plugging are on his forehead.

Jeter’s hitting has generally overcome his fielding deficiencies. In his stunning 2006 (should have been MVP) season, his offense helped the Yankees to a superb 6.9 wins above a replacement player.  However, as his slugging went south he declined to 3.5 wins in 2007 and 2.5 wins in 2008.

If Jeter holds steady or declines, he may just nose above all-glove, no bat Adam Everett, projected as a 1 to 1.5 win player next year, possibly more if healthy.  On a level plane Jeter is better, though he makes $21.6 million compared to the $1 million the Tigers pay Everett this season.

Jeter can no longer field his position effectively. Â Moving him would help what has been the worst defense in baseball.  Mark Teixeira blocks his natural progression to first base.  They have a glut of corner outfielders.  The logical move may be to center, though that’s no easy switch at age 35.

Sentiment keeps Jeter at short, but what’s now untenable could become catastrophic.