The Curious Case of Felix Hernandez

During last night’s Fantasy Baseball Roundtable radio show that I participate in every Wednesday night, I was asked in one of our regular segments whether Felix Hernandez would remain an effective pitcher after the age of 30. On the surface, this seemed like a pretty absurd question. Of course he would! What would make anyone think he wouldn’t? This article won’t actually answer that question. However, when quickly scanning the King’s statistical record in order to determine my response, there appeared to be some crazy things going on. I would like to share those with you.

First, the calculus behind the question could be summed up by the following graph:

This probably isn’t all that surprising. Since the beginning of last season, we’ve published several articles about Felix’s missing velocity heading into this season. Well, it has declined even further in 2013, albeit by a minor degree. As a rookie, he was averaging nearly 96 mph with his fastball. He is now averaging just under 92 mph for the season. Normally, this is ominous for a young pitcher’s future. But curiously, check this out:

It doesn’t line up perfectly, but the trend has been that as Felix has lost velocity, he has increased his strikeout percentage. That’s just not normal. It’s what makes him King I guess. His SwStk% also sits at a career high, despite the career worst fastball velocity. Just another oddity to add to the list.

But perhaps the strangest thing I came across is the separation between his fastball and “change-up”. You will see why I decided to wrap quotes around that so-called offspeed pitch. Have a look see at this chart:

Hmmm. So as Hernandez has lost velocity on his fastball, he has thrown his change-up harder? When he debuted, he featured a typical separation between the pitches of 10-11 mph. It’s difficult to tell from the chart, but according to both the BIS and PITCHf/x data, Hernandez is only throwing his change-up about three miles per hour slower than his fastball now. How exactly is that working as a change-up? I might question the pitch classification algorithm, but can both data sources be mistaken? The only thing I can think of is that his sinker is getting confused with his real change-up and inflating the average velocity reading. This could be some of the explanation, as his change-up velocity spiked in 2010, the same year in which half of his previous fastballs suddenly became sinkers and his change-up percentage tripled.

If you peek at the PITCHf/x overview, you’ll notice that his change-up’s max velocity this season is at 91.7. Umm, that’s not a change-up. So it seems pretty certain now that there are pitch classification errors going on here.

One more awe inspiring stat: his fastball, once again at its lowest average velocity in his career, has induced the highest SwStk% of his career. His previous career high was in 2007 at 7.4%. This year it has come in at 10.2%, quite a significant increase. It’s a pretty big testament to Felix that he has been able to adjust and remain as effective as he has (even more so even, as his SIERA is at the lowest of his career), in spite of a fastball that has lost steam.

So is Felix Hernandez going to remain successful after the age of 30? It’s hard to bet on a 27-year-old who has consistently lost fastball velocity, but then again, it’s hard to bet against someone who shows absolutely no signs of the decline actually affecting his performance.