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Astros prospects: Aaron West mechanics analysis

In-depth breakdown of Aaron West's mechanics with scouting grades and joint segment measurements.

There is no such thing as a pitching prospect..aka TINSTAAP. It’s a phrase that gets thrown around quite often, and often gets misused. It’s the theory that there is only so much life in a pitcher’s arm and you have no idea when it’s going to expire. It’s been adapted now to include the randomness in which pitching prospects fail.

Part of that whole process has to do with how unnatural the act of pitching actually is. It simply is not natural to throw a baseball 90+ miles an hour and manipulate it to move in whichever direction we can.

However, all of that ties back to a pitcher's mechanics. Over the last several years, many mechanical experts as well as engineers and scientists have made a lot of headway in figuring out how to improve pitchers’ health and force production. It’s hard to argue against the research into pitching training working as the average fastball velocity in the majors has been increasing over the last several years. However, the injury aspect is still lagging behind. But, there have been some components of mechanics that have been identified as "red flags" for potential injury.

I say "red flags" because there is no such thing as an absolute. Some pitchers are less affected by the added stress some of these components produce than others. Currently, there isn’t a way to truly predict those things to my knowledge. That’s why we have pitchers who never have injuries despite the dreaded "Inverted W" (gets too much play and thusly over scrutinized), while others are seemingly doomed with injuries.

With that said, one of the biggest areas of advancement in terms of mechanical analysis is the use of high-speed video. Kyle Boddy of Driveline Baseball (and former TCB Podcast guest) has made major strides using this method (among other tools) and its use is growing heavily in professional baseball.

We’re going to do a little bit of it today with some high speed video that Kyle Boddy shot of Aaron West during his last college season.

Note: Norm data is from Boddy’s research that he has posted on Baseball Think Factory. Also, I won’t be posting the stills from my analysis as I’m a graduate student with limited funds and won’t spend the $100+ for the Mac compatible program; instead I use the unlimited DEMO version that has a massive DEMO across the video.

I’ve discussed some mechanical basics with Aaron and he reports that he hasn’t made any mechanical changes since becoming a professional and has only worked on being more consistent and repeating his mechanics better. So, while there may be some slight changes in angles, this can give us an idea of the foundation of his mechanics.

West starts off on the first base side of the rubber and has a very mild hip turn during the lift phase of his delivery. He raises his knee to 70% of his height and Boddy’s research indicates elite pitchers raise their knee to 60-70% of their height. He’s at the max of that range and sets him up nicely for using his stride leg for momentum.

Speaking of momentum, West does a great job of creating momentum with his lower body. He has a very controlled "drop and drive" that he combines with a good "hip drive" (think Roy Oswalt after he raises his knee). The combination provides plenty of momentum to carry him into a long stride length that his 83% of his height (elite pitchers are 75-90%), and maintain force production up the chain.

When he creates a solid plant foot, his arm is abducted 88 degrees (elite pitchers are 80-100 degrees) which leaves him safe from his elbow drifting too high and adding stress to his shoulder and elbow. He also doesn’t have a heavy loading of his scapula (all pitchers have some degree). His knee lead knee angle is 133 degrees (elite pitchers are 120-144 degrees). That indicates that he’s getting enough momentum to carry his weight forward where he’s not over striding and can use his plant leg to generate some force as well.

Here’s where we run into some areas of improvement. As his arm comes forward into forearm layback, he reaches a maximum shoulder external rotation of 166 degrees which is a little short of the 170-190 degree range of elite pitchers. It’s not much from the norms, but it’s a pretty important one as velocity and maximum external rotation are correlated.

At release point, he has 74 degrees of hip flexion in the lead hip (elite pitchers have 92-115 degrees). He’s lacking in this area as well which could be from his long stride length that is blocking his trunk. It’s tied with how his arm decelerates which is actually pretty clean. He also doesn’t have a firm front side, which contrary to traditional pitching philosophy is a bad thing, but I like it and helps his deceleration.

On a scouting scale, his momentum and balance are both solid 65 grades. His posture is a solid 60 grade. His repeatability is also a 65-70.

Nothing in his mechanics are real big red flags and I wouldn't be surprised if his lack of maximum external rotation has improved since his college days due to the more intensive stretching routine that he went through this year than when he was at Washington. An improvement in maximum external rotation would make sense given his improved velocity this season.