I have slowly been working on breaking Feldman's mechanics since the week he signed with the Astros. Since I'm just posting an article on it now, one of two things occurred; His mechanics are really difficult to understand or I just haven't been able to work on it.
Feldman's mechanics are not complicated.
There really isn't anything flashy about his mechanics. They're simple and repeatable. That's contributed to his good walk numbers throughout his career. You can go through and look at game logs of pitch fx data to see that he consistently shows a tight grouping of release points.
But, how does his mechanical measurements compare to elite pitchers.
Stride Length: 53 inches (67% of Height) [75-90% of Height]
Max Knee Height: 58 inches (73% of Height) [60-70% of Height]
Shoulder Abduction at Foot Strike: 60 Degrees [80-100 Degrees]
Lead Knee Flexion at Foot Strike: 135 Degrees [125-140 Degrees]
Max Shoulder External Rotation: 169 Degrees [170-190 Degrees]
Lead Hip Flexion at Release Point: 96 Degrees [92-115 Degrees]
Can you pick out which one I have a problem with? Yeah, the stride length. The max shoulder external rotation isn't within range, but nobody's perfect and neither are my measurements (there is always a percent error in every scientific measurement). The shoulder abduction is very low, but more on that later. The max knee height is also out or range, and is inversely correlated to the stride length in my opinion.
You see, the leg lift is where a pitcher is able to create a load (potential energy) that is then used to create momentum (kinetic energy). So, the higher the leg lift, the more potential energy and more momentum!
There is a timing aspect with this. If the leg lift takes too long, some of that potential energy is converted into kinetic energy to maintain the balance point instead of momentum to the plate. This is what goes on with Feldman as he just doesn't have enough momentum to the plate to create a long stride length. It carries him just 53 inches!
Here's a teaser for a future article, Anthony Bass has a stride length that is longer yet stands five inches shorter. Proof that tall pitchers don't always have a release point closer to the plate.
Although, what I'm not a fan of in his leg lift and stride length, he makes up for in a pretty good leg drive. He drops his back leg and drives forward so that he gets his weight over his lead leg. So, while he starts off behind the 8 ball so to speak, he catches up decently.
Due to the only high speed video I found being from the third-base side, I didn't evaluate the back knee angle at turnover. That angle is one that Astros pitching coach Brent Strom has started using in pitcher evaluations, so I did look at some other videos. The accuracy isn't nearly as good. Although, it is between 115 and 120 degrees which falls short of the optimal level of 105 degrees or smaller. Remember, that there are some accuracy issues with slower video rates and it could be smaller or larger, but not by a great deal.
Feldman primarily pitches off of a sinker so the high vertical movement associated with low back knee angles isn't as big of a factor as for someone who pitches off of a 4-seam fastball.
The low shoulder abduction component is an interesting one. I checked that one several times. At foot strike, he's leaned back some which skews the accuracy some, but not 20 degrees to put him within range. I'm big on that angle from a health standpoint. I like to see that angle in the lower part of that 80-100 degree range. I'm even OK with it to be a little lower. Once you start abducting the arm over 90, you begin to increase the risk of rotator cuff impingement and requires more dynamic stability coming from the rotator cuff which looses strength once pitch counts start climbing.
The downside is that his humerus is lagging behind where it should be and has more range of motion that the arm must be accelerated through to reach release point. So, while he protects the shoulder somewhat structurally, he increases the dynamic stress on the shoulder.
Overall, his mechanics are pretty basic, even at normal speed. Nothing flashy. He utilizes his strong legs and arms to create his velocity. The simplistic nature of them allow for repeatability, but he's not very dynamic and not overly efficient.