K-Rod's Velocity, Pitch Selection and Control (PITCHf/x)

Nat Boyle has a couple links and quotes about Francisco Rodriguez losing a few MPH. Apparently, this has at least the Mets a little gun shy on taking a five year deal on him.

Here's a key quote from the link

"K-Rod's agent, Paul Kinzer, insists that such talk is misinformed. He says that Rodriguez is more comfortable throwing his fastball at lower velocities because it gives him better command. 'I saw him hit 96 (mph) twice and 97 once late in the season..." Kinzer said Saturday. "The velocity is there when he needs to reach back for it. He told me he's just more comfortable around 92-93.

'He says he has a better feel for his change-up when he's not overthrowing his fastball, and his change-up has become a big part of his arsenal.'"

I'm not sure I'm buying Kinzer's line, but there's enough truth to make it somewhat legitimate. First, there's no doubt he's changed his pitching approach. Check out these selected quotes (and the link to the whole article if you're curious) before I move on the PITCHf/x data.

LA Times Sept. 2008

His fastball isn’t quite as crisp, but he’s locating it better. He still has two well-above-average breaking pitches, a curve he starts high and away and drops into the strike zone and a snap-hook slider that starts at the thighs and breaks into the dirt.

But the great equalizer this season has been his changeup, which Rodriguez dabbled with in 2005 and 2006, threw more in 2007 but has evolved into his pitch in 2008.

Playing winter ball in Venezuela, Rodriguez threw only fastballs and changeups, and he developed enough confidence in his off-speed pitch to use it regularly this season.

But early on, he threw it only to left-handed hitters. When Rodriguez began getting big outs with it, he started throwing it to right-handers in June.

Then, about a month ago, while playing catch before a game, he started experimenting with the pitch.

With a four-seam grip, Rodriguez could throw the changeup at about 87 mph and make it drop straight down like a split-fingered fastball. With a two-seam grip, his changeup broke right to left with some sink, at about 83 mph.

Rodriguez may throw a few variations, as you just read, but he's basically a three pitch pitcher. Fastball (FA), Change (CH) and Slider/Slurve/Curve (SV).

Here's a look at K-Rod's pitch mix, by batter hand.





It's quite evident he's changed his approach, and it carried over to the playoffs. There's a small sample for October 2008, which I'm not including in the next graphs. October 2007 was a minuscule sample, and dropped altogether. I'll just look at regular season games from here on down.

Now, about the velocity. Here are two looks at historical pitch speed for K-Rod. One only includes home games, to give some perspective without between-park effects.





Here's each Fastball by K-Rod, by game. Again, with and without road games. I'm seeing what looks like a dip, possibly a dead-arm phase, in July/August.





So, what Kinzer says about velocity is accurate, but I'm not so sure what is meant by "more comfortable". How about the command? I don't know where he was aiming, but here are some accuracy numbers. Strike zone is based on the rule book with and the PFX operator settings. The "paint" covers the additional space you'd have if the plate was 24 inches, instead of 17. That is actually how batters see, and, for the most part, umpires call a strike zone.

The fastball really doesn't look too become much more accurate late in 2008, based on these measures. But the change-up does. For most of 2007, he threw very few change-ups, so, as you move left-to-right in that graph, the sample sizes go from as little to 8 to as many as 51.





It's not a perfect relationship, but, when Rodriguez had the least velocity on the fastball, he also threw less strikes. It does look like the accuracy suffered over the time the speed was actually beginning to come back. I would be hard pressed to claim the slower 2008 version is more accurate, as this data doesn't fully support that, and isn't sufficient (where was the catcher's mitt?) to fully address the issue.

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Not to say he isn't a more effective pitcher with these new variations on his stuff, but there may be more about Francisco Rodriguez and his pitch speed and selection than Kinzer is letting on. More questions remain, but, so far, I think the Mets are very wise to be cautious.