Appreciate the feedback.
His is 5"6" tall and his stride is ~5’ from front of rubber to his front foot heel (in this case there is small piece of tape on the ground representing the rubber). I know this because, I have a video analysis tool that measures distance and velocity. During his stride and hip rotation, his back foot travels significantly forward. So at ball release the distance between his feet is reduced. However, the distance between his front foot and the rubber (tape in this video) is ~5 feet. No doubt his stride has room for improvement, and stride (driving down the mound) is one thing that I always remind him of. We’ll continue to work on that.
Head out over front foot and flat back
You made me think more deeply about this. My son releases the ball off of a straight front leg. His straight leg is maintained through follow through. This straight front leg posture is most pronounced on his “I mean it” fast ball. In this video he is dissipating some of his energy by rising up on his front foot toe. I need to see if that happens on the mound too. I think that the snap shoot you took at ball release was on his first few pitches (from the stretch) and his intent to really let it go hard wasn’t quite there, so his front leg had a slight knee bend.
I think (and I am guessing a bit) that it is more difficult for a “straight leg” pitcher to get his head out in front compared a “bent knee” pitcher. It seems that if a “straight leg” pitcher bent over to the same degree as a “bent knee” pitcher that he would have difficulty maintaining balance in follow through. Said differently, the “bent knee” pitcher has much better ability to use his quads/butt/back to control body deceleration and posture in the follow-through. I see the same things in Justin Verlander’s fast ball mechanics, namely straight front leg, fairly upright back, and head behind front foot. See the top video clip of JV; http://www.letstalkpitching.com/t/video-justin-verlander/16803. The lower clip appears to show off-speed pitches, cause he is clearly bending his knee.
I am not saying that it’s right or best way or that my son doesn’t need to improve on his mechanics. I am simply making the observation and comparison. One question that comes to mind is; is a “straight leg” pitcher more susceptible to arm injury?