Jeter is about to finish up arguably his worst season. What happened?

A superficial look at Derek Jeter’s overall stats makes it appear that this season is on the low side of his career norms, but not terrible. After all, how bad can a guy be if he bats .314/.385/.431?

By more advanced metrics though this may be Jeter’s worst season. According to Baseball Prospectus’ BRAR and BRAA metrics, namely batting runs above replacement and above average, Jeter is at 31 and 13 respectively. These are the worst marks since his first full season in 1996.

To put it in perspective, Jeter is still having a nice season. Right above and below him on the BRAR list are Brad Hawpe and Chone Figgins above him and Ryan Zimmerman and Paul Konerko below him. Good for other players, but bad for Jeter’s lofty standards.

Even his counting stats are way down. His 89 runs will likely result in this season being the second lowest of his career, his 13 steals is a career low, though he has two weeks left. He has been caught stealing almost 40% of the time. Month by month his core stats has been dropping like a stone:

What is going on? Jeter had a 38% hit rate earlier this year, now it is down to 36%, his career norm. So, the BA is in line with his career norm, but it has been undergoing a steep and steady decline throughout the season. This is reflected in his xBAs (expected batting averages) month by month: .245, .313, .322, .274, .248, .232. His skills have not supported a .275 BA in four of the six months of the season.

His contact rates has also been dropping. From April to September: 90%, 88%, 85%, 82%, 83%, 82%. So with a decrease in power, a decrease in contact rate leads to the very low xBA numbers.

Can this be blamed on his sore knee? In a recent Under The Knife column, Will Carroll stated:

The Yankees are having a small problem with Derek Jeter–he wants to play. The problem is really in Jeter’s knee, where what the team is calling patellar tendonitis is causing him pain and some decreased speed and range. A couple rest days here and there would help, even if the problem is deeper inside the knee, as I believe. Jeter, on the other hand, believes he helps the team more on the field, but if Gene Monahan and his staff are telling him to sit, there’s likely some longer-term concerns. If Jeter’s knee were to get worse, it could cause a longer-term loss of the Captain, which would be much more problematic heading into October

Since Will believes that the problem is deeper inside the knee, I have to conclude that the knee problem is to blame. It certainly is to blame for his low SB total. Jeter has only 13 SB, but more interesting is his career low 11% stolen base opportunity rate. He is only stealing in one out of every nine opportunities, and the number is even less in the last two months. Jeter has simply stopped running.

If he is not running it is because he recognizes that his knee is sufficiently hurt that he just can’t do it. For a guy willing to dive headfirst into the stands, this is a significant factor. Let’s see what the offseason brings. I will be keeping a close eye on the medical reports in the offseason.

As an aside, I am a big Yankee fan, and read the Pinstripe Alley blog. They had a great pic of the autograph given to a fan by Shelley Duncan. You have to love the guy! Here is the link for your enjoyment.

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