The Changes in VandenHurk's Pitches: A Pitch f/x Attempt

The Marlins currently have a glut of starting pitchers at the upper level of the organization, most of whom have questionable futures on the team. After Josh Johnson and Ricky Nolasco, the team has five potential starters facing different issues in their quest to fill in the remaining three rotation slots.

Occasional Maniac reader nny mentioned over at the SoFlaMarlins boards that VandenHurk appears to be a significantly better pitcher than Chris Volstad

RVH has the potential to turn into a Ricky-lite if he can continue to improve his control. You look at their repertoire, they have the same 4 pitches (Fastball, Slider, Curve, Change), all outside the curve have idential velocities, although RVH looks like he might just abandon the curve, having thrown it just a couple dozen times this year.

No, RVH’s stuff don’t match ricky’s, but the biggest difference between the two is also location. And the difference between this year and last year is the fact that RVH has taken a major step forward with his location, being just 24 years of age he could continue to take step forwards. Even if he doesn’t, he still displayed above average control this season.

Factor in his ability to rack up K’s and he should have a very decent K/BB rate. Much like Ricky his problems are going to be FB’s and XBH. But, I mean, even if he doesn’t become Ricky, what’s he likely to become? A #3-#4 just like Volstad?

I disputed his point to some degree over at the thread of question, and I won’t do that so much here. What I will do is take a look at the changes that VandenHurk has made and whether those changes have yielded a net positive or negative effect. Unfortunately, 2007 data from Pitch f/x is questionable or not available from my usual source, Dan Brooks’ site Brooks Baseball, and VandenHurk only pitched four starts in 2008, so I’m just going to look at his 2009 data with Pitch f/x.


Pitch % thrown MPH pf_x pf_z
Fastball 66.4% 91.8 -7.9 9.4
Slider 22.5$ 83.9 1.4 2.3
Changeup 8.8% 84.2 -7.5 6.2
Curveball 2.2% 75.4 5.7 -7.0

(Note: All classifications from FanGraphs, sinkers/two-seamers were switched to fastballs and adjusted accordingly. Intentional walks and pitchouts were not included.)

You can see decent separation in the chart between VandenHurk’s fastball/changeups and his sliders and curves. It’s been well documented that during the World Baseball Classic this March, VandeHurk worked and talked extensively with Netherlands coach, fellow Dutchman, and (should-be) Hall of Famer Bert Blyleven. One of the changes that came about from talking and working with Blyleven was the change in usage of his slider and curveball, resulting in a drastic drop in the use of the curve and subsequent increase in the use of the slider. According to FanGraphs, in 2007 VandenHurk used the changeup 13.1% of the time and the curveball 12.1%, while the slider was only used around 5.0% of the time. This season, VandenHurk went to the slider 22.5% of the time and almost abandoned the “Holland Hammer,” going to it only 2.2% of the time (about 22 times).

So how good has the slider looked? Here’s a look at the slider compared to his other pitches.

Pitch # thrown In Zone% Watch% Chase% Whiff% GB%
Slider 223 52.0% 39.0% 31.0% 14.0% 45.9%
Total 988 55.4% 40.0% 27.4% 16.2% 29.1%
League* —- —- 49.3%** 25.1% 20.5% 45.1%

*League value for GB% attained from batted ball data found on Baseball-Reference. All other data available found on FanGraphs.

** Watch%/Chase% values from FanGraphs not necessarily based on same strikezone as my own, so results may vary.

In Zone%: Percentage of pitches landing in the defined strike zone
Watch%: Percentage of pitches taken that were in the strike zone
Chase%: Percentage of swings taken out of the strike zone
Whiff%: Percentage of swings and misses out of total swings
GB%: Percentage of ground balls over balls in play (includes bunts)

It is worth noting that I did the lefty-righty splits for VandenHurk as well and got ridiculously similar numbers for these rates for either side, indicating that VandenHurk did not show much of a platoon split this season, though this disagrees heartily with the batting against results as shown here. That oddity aside, let’s take a look at this data.

The one thing that pops out in my mind when comparing the slider to his totals is how similar they are as well. It makes obvious sense that he’d be able to place his pitches as a whole better than he does his slider, but his slider stayed pretty close to the zone as well, uncharacteristic of most sliders which are predominantly located low. The slider location chart agrees with the assessment that many of VandenHurk’s sliders actually landed in the zone and in good places to hit as well. Likewise, while the slider was inducing more chases out of the zone, it was also inducing slightly fewer whiffs, another oddity as the slider is typically an out pitch for a pitcher. All in all, given the small samples, it would be fair to say that VandenHurk’s slider appears to be more or less equal to his average pitch.

However, one notable difference is in the rate of ground balls induced. Now again, this is a small sample, not even close to a full season in terms of pitches thrown. However, in the 223 sliders thrown by VandenHurk, he induced 45% of the balls in play as grounders, significantly higher than his overall ground ball rate of 29% as given by Baseball-Reference. This may be one of the more important developments in VandeHurk’s use of the pitch. If the slider proves to be capable of inducing more ground balls, it could mitigate its diminished effectiveness as a strikeout pitch in favor of allowing VandenHurk to maintain a decent grounder rate and subsequently keep the ball in the park. In his brief stints in the majors, VandenHurk has shown to have extreme fly ball tendencies; FanGraphs has his overall FB% for his career at 47.9%. As we all know, fly balls can lead to a significantly larger amount of home runs, so any pitches that help VandenHurk either keep the ball on the ground or out of play and going to be more than beneficial given his batted ball profiles.

So, from what we’ve seen of VandenHurk’s slider, it has proven to have a twofold effect. Its first effect was fairly obvious; eliminating the curveball allowed for an increase in control and strikes for VandenHurk, which could help in dropping his walk rate. The other effect is that perhaps the change to the slider can help VandenHurk bring the ball down a little more and minimize the home run damage. If he can continue to spot it low in the zone (he has not done a great job of it so far, based on the location chart), he may have success inducing more swings and misses and weak contact, something the curveball was definitely struggling to do. The addition was a definite improvement over the Holland Hammer.

Tags: Miami Marlins Rick VandenHurk

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