Luckily, Wilson is generally fundamentally sound and very accurate. Most his misses are normal incompletions, not tied to any one, reoccuring reason.
He does have the occasional bad miss, though, which is the tendency for his throws to sail on him. That's mechanical. Now, having a ball sail on someone is different than over-throwing their receiver. Over-throwing someone seems to imply that he is lacking touch or his aiming point is off. I don't believe thats the issue with him, at least not with his bad misses. (He does occasionally over-throw receivers, but I wouldn't call that a bad miss, just normal incompletions.)
As to the ball sailing on him, the ultimate reason for that, in my experience, is the person is usually releasing the ball a split-second to early at the top of their throwing motion. I fought with this same problem in pitching and it usually came down to a couple reasons, but with Wilson, I suspect (without going back and watching each bad miss) that the one reason it is happening to him is, like many already said, because of his feet work. More specially, him landing his plant leg to far out in his stride. When your base is to far spread out, you dont get the right follow-through bend at the waist, and your arm cannot reach out towards your target like its suppose too. Your body is also shorter with a wide base, and with Wilson's height concerns already, he may even feel the need to release the ball right at its highest point so mich, that instead he throws it a tad too early.
It really is a matter of a few inches in where he releases the ball. I think he continue to work on it and improve, but I think it'll be one those reoccurring issues throughout his career, mostly because of his over-the-top high release point.
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