I mentioned BALANCE throughout my last post and I’d like to expand on that point here.
Regardless how bent, or not, your front leg is, there’s a reason for each pitcher conducting his overall motion and momentum. Take a look at the pitcher below and you’ll see a definite bend in his stride leg at the end of his release cycle. You’ll also notice how well he balances himself off in order to control his ending posture, thus putting a control impression on his pitch. This ending posture is not shear happenstance or “it’s just there.” He’s worked very hard to control his body as he progresses down the mound and end his body in a posture that impresses balance, overall and completely.
Notice that his stride leg is somewhat bend, ending his finish -but, he didn’t just consider that as an end in itself. He used his pivot leg as a balance weight, with a center point of his overall extensions - front shoulder, ending arms and so forth, in the midsection just above his beltline.
Now regardless of the different ending finish that a pitcher has, those that can control themselves all use this weight proportion in their total progress - from set up to delivery.
Adding to what I’ve already mentioned, some pitchers actually bend their stride leg with a very pronounced bend, then use the knee as a hinge to right the lower portion of their body up a bit when ending their delivery posture. These guys have a great deal of muscular strength in the core. Take a look at the pitcher below and you’ll see how his body is not only balance with proportion, but he went from a stride leg bend to an extension of that bend.
For those pitchers that have a more upright posture in their finish, their stride leg is bent slightly but they still maintain a body posture that balances themselves off, while rising up from a more pronounced bending of the stride leg.
You’ll have to fine tune and decide what works best for your overall strength and progressive maturity. Just be mindful of the purpose for every move and direction that you take during your overall body’s chain of movement.