Is Ichiro Declining?

Year in and year out, Ichiro is a model of consistency. He has had over 200 hits and a batting average over .300 every single season he’s been in the majors. He’s also scored at least 100 runs every year, and stolen at least 30 bases. That being said, what can we expect from 2009?

The short answer, of course, is more of the same. When a player is this consistent for this long, the best predictor of his performance is his past performance. With that in mind, Ichiro is also getting older – he’ll be 35 next year, and even though he is a unique player, he’s not totally immune to the effects of aging. In fact, this is already beginning to show up in his batting average.

In 2008, Ichiro hit “only” .310 – the second lowest batting average of his career (in the North American Major Leagues, that is). However, he managed this batting average despite a higher-than-expected BABIP – his actual BABIP was .330, but his expected BABIP (according to a new model I introduced) was .307.

Before you tell me that Ichiro is unique, hear me out: yes, I agree that Ichiro is unique, but this new model attempted to incorporate many of the elements that make Ichiro unique – such things as hitting to all fields and speed, two elements of which Ichiro makes particular use.

I wouldn’t disagree that, even though the model has attempted to incorporate the unique aspects of Ichiro’s game, it hasn’t fully succeeded. Here are Ichiro’s expected and actual BABIPs since 2005:

Note the average: since 2005, the model has underrated Ichiro’s BABIP by approximately 23 points. Now, I think this is somewhat unfair, as the average is severely skewed by Ichiro’s incredibly-high BABIP in 2006, which was well out of line with even his own already-high numbers. But if we assume that the ~23 point difference is correct, well…that means Ichiro’s BABIP in 2008 was completely luck free.

What’s perhaps more interesting to note is the downward trend of Ichiro’s expected BABIP – it has declined each year since 2005. This goes along with conventional aging patterns – Ichiro was 31 in 2005, and as he exited his prime, his expected BABIP slowly dropped.

This suggests to me that Ichiro’s batting average is a lot more likely to go down than it is to rise. Of course, it’s certainly possible that he has another flukey BABIP year that allows his BA to rise once again, but this is increasingly unlikely as he gets older. Even though Ichiro’s .310 batting average was the second lowest of his career in 2008, it doesn’t appear that this was a fluke, but rather was indicative of him slowly getting older. That doesn’t mean Ichiro won’t have significant value in fantasy leagues next year – after all, he’s still shown that he can steal 40+ bases and hit over .300 – but don’t draft him expecting a resurgence to the AL batting title.