Please read Chris’s post from this morning before reading past the jump.
Chris, via a reader, asked the question today: From where did Madison Bumgarner’s jump in strikeouts come in 2011, and where have they disappeared to in 2012? I think the answer to all of this is in his slider.
Well, according to Fangraphs, Bumgarner struck out 19 percent of batters with the slider in 2010 and 15 percent of batters on fastballs. In 2011 that number jumped from 19 to 28 on sliders, while the fastball strikeouts increased to 19 percent of the time. Thus far in 2012 he’s been missing fewer bats with the slider at just 19 percent to 18 percent with the fastball. That said, as evidenced by Chris’ post, that number has really been building over the course of the season — his low strikeout rates don’t seem poised to continue.
Also according to Fangraphs, he threw the slider about 18 percent of the time in 2010. He threw it 28 percent of the time in 2011. And he’s throwing it 34 percent of the time in 2012.
On top of that, the pitch has changed. He averaged a velocity of 84.4 in 2010, but he’s since upped that to 87.2 over the past two seasons. That’s coincided with less horizontal movement, making it more of a straight-down and less-slurvy pitch that tends to miss more bats. (Unless your Romo. Romo’s doing it right with the slurvy slider.)
Here are the velocity charts for his slider over the past three seasons from ESPN Stats & Inforamtion.
So what has been the cause of Bumgarner’s improved strikeout rates as he’s matured? More and better sliders. As he settles in this year, I expect it will continue to be a really good swing-and-miss pitch for the young left-hander, and that his lack of strikeouts in the early goings of 2012 was just a matter of small samples and settling into his groove.




