When Michael Pineda came up, he came up as a guy capable of consistently throwing his fastball in the mid- to high-90s. Given his stature, that made us unreasonably excited, and sure enough, we've seen him blow some hitters away with 98 and 99mph heat through the season's first few months.

But on many occasions, we've also seen Pineda dial it back. This was worrisome at first, since we're all hyper-observant and overprotective. Then we came to learn that Pineda was doing it on purpose to conserve his energy for bigger spots. I don't know how well that works for him, but I'm certainly not going to bicker with the thought process. Starters don't need to throw their fastballs as hard as they can every single time.

Thinking about Pineda's fastball got me wondering how effective it is at lower and higher velocities. So earlier today I dove into the PITCHfx data, pulled out all of Pineda's fastballs, and split them into three groups by speed. These groupings won't be perfect since PITCHfx velocity data isn't 100% accurate park-to-park, but this should still give us a pretty good indication. The results:

It should come as little surprise that, at least in the early going, Pineda's hardest fastballs have been his best fastballs. The sample sizes here aren't huge, but they're not tiny, and Pineda's best speeds have generated the least contact, and the worst contact.

But while Pineda's slower fastballs have been less effective than Pineda's faster fastballs, they've still been quite good. Just for the sake of a quick comparison, Tim Lincecum's fastballs this season have gone for 62% strikes, with 86% contact and a 38% in play rate (when swinging). A pitcher's fastball is important, but a pitcher's fastball usually isn't a big weapon. Michael Pineda's fastball looks like a weapon, even when he eases up on it a little.

We'll see how this holds up over the rest of the summer, as Pineda gets more innings on his arm and other teams grow more familiar. I don't have a grand, sweeping conclusion here. If there's one thing I want you to come away from this thinking, it's that, hey, Michael Pineda's hard fastball is really good, but his slower fastball seems pretty good, too. Just as we'd expect, since Pineda's huge, and his slow fastballs are still fast fastballs. He still needs to improve his slider and really improve his changeup, but his fastball is one hell of a building block.