May 9, 2012 at 1:19 pm by David Lee under Atlanta Braves, Player Analysis
Much has been made of Tommy Hanson’s velocity trends. His fastball has dipped from 92 to 91 to 89 over a three-year span, inciting the usual concern a fan base has when one of its prized arms doesn’t throw as hard as it used to.
Aside from drastic drops in both velocity and movement that usually spell some other issue like injury, I have never been one to panic over velocity trends. Pitchers adapt to how their arms handle workloads, and the more innings they record, the more adapting it can take. This could mean a slight drop in velocity to induce more contact for shorter at-bats, taking some off to preserve endurance, etc.
Brandon Beachy is currently making said adaptation, knocking a couple miles per hour off the fastball and losing a good chunk of strikeouts, yet lowering his walk rate and pitching deeper into games. It should be noted Beachy’s BABIP is currently .226, and a 1.62 ERA will regress, but so far the adjustments are going well.
For Hanson, he has also seen drops in velocity among his other pitches. How it has affected his slider and what adjustments are being made is the focus here.
Hanson’s slider averaged 84 miles per hour in 2010, when he struck out batters at a rate of 20 percent with a 3.31 FIP. The pitch showed good movement and received a whiff/swing rate of 30 percent, while his ground ball/in play rate was 46 percent and his line drive/in play rate was 13 percent.
In 2011, the slider dropped to 82 miles per hour and picked up a couple ticks of downward movement. He threw it the same 28 percent of the time, receiving a five percent increase in whiffs per swing.
So far this year in 39.2 innings, Hanson’s slider has dropped another mile per hour to 81, has maintained the same amount of downward movement and is receiving a whiff/swing rate of 39 percent, a 9 percent increase from 2010. His ground ball/in play rate has also jumped to 59 percent, and his line drive/in play rate is only 9 percent while being thrown 30 percent of the time.
The problem lies in the fact that Hanson’s slider, despite getting more movement, is not as deceptive as it was, according to swing numbers. In 2010, batters swung at the pitch 47.5 percent of the time. In 2011, it was 46.39 percent. This year, it’s 44.14 percent.
So while Hanson’s slider is getting more movement, perhaps the decrease in velocity has led to some loss in deception. The pitch is seeing more whiffs, but it’s also seeing fewer swings, negating some of its value.
In fact, aside from the curveball, the rest of Hanson’s pitches have seen a decrease in swing rate, possibly a result of little deception.
If you’re looking for a comparison going the other way, take a look at Clayton Kershaw. The Dodgers left-hander averaged 81 miles per hour with his slider in 2010, receiving 43 percent whiffs/swing. Jump to this year so far, he’s throwing it 85 miles per hour with slightly less movement, but his whiff/swing rate is 47 percent. The difference in swing rate between 2010 and 2012 is 42.95 percent and 50.25 percent.
As I said in the beginning, I have no problem with slight decreases in velocity as long as the pitcher adapts. But Hanson’s stuff doesn’t appear to be adapting well to the decrease, and I feel it’s enough to consider whether a downward strikeout rate is in the forecast, especially with the lack of swings. Yes, his slider is seeing more whiffs per swing, but as mentioned previously, fewer swings negates much of this value. And it’s to the point where he’s losing total whiffs on the pitch.
Numbers courtesy of Brooks Baseball.