Felix Hernandez and the Fastball

It's funny that a lot of people who read the Mariners blogs these days haven't been exposed to the saga of Felix Hernandez's fastball. These people are lucky. They've never had to read about Felix throwing 23 fastballs in a row to lead off a game and get shelled in the first again. They've never spent hours analysing the way that the greatest hope of the franchise attempted to piss everything all away in an attempt to establish his pitches whilst feeling all manly-like. They've never spent hours agonising whether Felix will ever pull it all together, because now he has.

But for a while, things were looking pretty dicey. It's hard to believe now that Rafael Chaves, our 2007 pitching coach, had to resort to handing Felix a letter from Dave to try to get him to stop throwing fastballs so much. Back then, throwing 90% fastballs for the first four innings was the norm. And it was infuriating. Batters knew exactly what was coming, and no matter how good your fastball is, you can't just blow major league hitters away without changing things up at all. Felix showed flashes of potential through his first three and a half seasons with the club, seeming to take steps forward only to revert back to his old self the next start. So that was no fun. If he'd just cut down the predictable fastballs, we thought, we'd really have something on our hands.

A funny thing happened in 2009, though. He didn't cut down his fastball. Instead, it got better (by Fangraphs wFB/C). And at the same time, it got slower. Observe (and ignore 2005, as it's a partial season):

Figure 1: Felix Hernandez's seasonal fastball velocity and fastball value

Felix has lost more than 1.5 miles an hour off his fastball since 2007. That decrease corresponds to an increase in wFB/C of 1.41 runs per 100 fastballs thrown. I don't think the run values mean that much, as they're hugely influenced by his defence, but it's still striking to see how well velocity and value match up. And while he's throwing more fastballs more slowly, he's also working his 90mph death-change (his changeup is really, really, really good) in there more often, mixing pitches and keeping batters guessing. So the above isn't really a useful piece of analysis so much as an interesting little dataset and a chance to reflect on the times before Felix had truly ascended his throne.

Two seasons ago Felix threw as hard as anybody in the majors and couldn't get results. Now with experience, a filthy changeup, a resurgent curve, and a friendly defence on his side, he's a Cy Young contender at 23.

It was worth the wait and the struggle, wasn't it?