The Case of Doug Fister's Velocity

If you're not listening to the TCB podcast, you probably should (selfless plug).

Before the season started, we discussed the out of the blue signing of Doug Fister and what the Astros might be seeing in the former top of the rotation pitcher.

One thing that Chris and I both looked at was his pitch usage. His usage is very sporadic over the years and not much consistency. We hypothesized that the Astros saw something that they could fix and revert him back to some of the tendencies that made him successful. That's not what we're looking at here though. (Hey Chris, sounds like an article idea).

The other aspect of our discussion was that the Astros had to figure out how to regain his velocity. His velocity had gone through slight decline culminating in about a two mile-per-hour drop last season to 86.68 with his sinker. His most productive years averaged 89-90 with the sinker.

During Spring Training, Fister showed some signs of that with several 90 MPH pitches but once he started stretching out that velocity declined to the point that he started the season at 85-86 MPH with his sinker. Exactly what we feared.

As the season has worn on, that velocity has actually begun to increase to the 88 MPH average in his most recent start against Oakland.

BrooksBaseball.net

Something had to have changed. Pitchers don't just pick up velocity after loosing it in most cases. One of the things that we discussed early on after Jeff Luhnow hired Brent Strom as pitching coach was his philosophy. Strom is a big proponent for momentum which is one of the reasons I thought that Josh Fields fit this team so well.

Momentum can be discussed ad nauseam but the main thing to keep in mind is that Strom likes to get pitchers moving towards the plate for several reasons. It helps with hip drive, forward rotation, and deceleration path. All very important things. The body is a kinetic chain and momentum can only help with kinetic energy so it's way to more efficiently throw a ball.

Doug Fister at Mil

This is Fister's first start of the season against Milwaukee. It takes fifteen frames for Fister's knee to reach his max knee height in his leg kick to the release point.

Doug Fister at Seattle

In Fister's fourth start of the season, it took him thirteen frames to get from max knee height to his release point.

Doug Fister at Oakland

In his most recent start against Oakland, it took him just eleven frames to reach his release point from his max knee height.

Given the frames per second limitations of MLB.tv, this isn't as accurate of a measure as I'd hope and could get with a high speed camera. But, it does fit the trend that he's getting more momentum and speeding up his delivery.

So, lets look at how Fister could accomplish this and solidify that he's made some mechanical improvements.

This is Fister's max knee height in the first start of the season. Look how straight his back leg is and how he's balanced over that leg. He does have some rotation back towards left field to torque the hips some.

You can that in his fourth start of the season that there's a little bit more flexion in that knee but he's definitely torqued a little bit more with his hips.

This is really where you can see a difference. The difference in just one start. Fister has more flexion in that back leg and you can actually see how he's pushing out with his lead hip. That's called hip drive and is a way to get momentum going towards the plate by just pushing your hip towards the plate early in your delivery. The hips are actually your center of mass, so your momentum goes where your hips go.

So, Fister is definitely getting more drive out of his back leg to allow for his momentum to get moving towards the plate.

But, is the added momentum allowing for better forward rotation and improved declaration paths?

This is where he's mostly decelerated and he's rotated some. See how his head is in line with the elbow from this angle.

In his fourth start, he's getting just slight more rotation. However, as mentioned before, this could just be a limitation of the frame rate.

In the start against Oakland, he's more rotated around that stride leg. It's causing him to fall off more to the first base side (and something he did some in the Milwaukee start), which doesn't help fielding at all. But, it shows better rotation and momentum.

This is not overly definitive. But, he's definitely showing signs of improving momentum towards the plate that is consistent with his increase in velocity (and effectiveness). It's something to watch in his upcoming start. Does he continue to have the improved momentum and does the velocity continue to creep up into the upper 80's. I don't think he'll ever return to the form he had with the Tigers, but with the upper 80's sinker, he might be able to keep his spot solidified in the rotation. Something I was questioning a few weeks ago.