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Nice guy.  Have some blogs.  Do baseball research.

Monday, September 12, 2011

Is Jeter juiced?

This is a fundamentally unfair question, one which has not been asked much since the steroid hysteria died down 2-3 years ago.  However, the improvement in the performance of Yankee icon Derek Jeter forces one to address it.

See my post: WEDNESDAY, DECEMBER 1, 2010

Yankees beware: Jeter's production is likely to decline.

See data for Jeter for full seasons 2008, 2009, 2010 and for 2011 both before and after Jeter's return from Florida following his rehab from injury.  Jeter's improvement is inexplicable.
A-Rod's cousin
Did Jeter run into A-Rod's cousin, the one who provided A-Rod with performance enhancing stuff a few years ago?

I looked at:
BA: batting average
OBP: on base percentage
SLG: slugging average
OPS: OBP + SLG

Jeter's percentage improvements in 253 PA (plate appearances) after returning compared with 293 PA before:

BA            OBP           SLG        OPS
29.89%    20.23%    42.14%    30.98%

Here are his actual 2011 numbers:
age BA            OBP           SLG        OPS
36  0.260    0.324    0.324    0.649
37 0.338    0.3895   0.461    0.850
dif 0.0777 0.0656 0.137    0.201

Jeter's OPS his three previous seasons:
2008 .771
2009 .871
2010 .649

Jeter's 2010 OPS is exactly the same as his 2011 before Jeter left the Yankees to rehab: .649, the lowest of his career.

What the heck happened in Florida and don't tell me Jeter adjusted his batting swing?

The sample size is approaching a half season so the question is legitimate.  For his career Jeter does tend to improve in the second half: OPS .820/.846.  For the last three seasons:
2008 .764/.778
2009 .908/.836
2010 .790/.633

Jeter snapped out of a slump that had lasted through the second half of 2010 and the first half of 2011, from which Jeter exploded after turning 37.  How often does that happen without an extra boost?

Jeter has cleared .900 OPS twice:
1999 .989
2006 .900

His 2011 post injury OPS is .850 through 9/10/11.  In only six of Jeter's 16 full seasons did Jeter have OPS greater than .850.

What the heck?

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