10 pages in and no one has posted these stories-
He apparently had a great QB coach at Mississippi State.
http://gridironnow.com/mississippi-state-coach-dan-mullens-work-with-qbs-is-notable/
"With his work with Prescott, Mullen continues to show why he is considered one of the best in the nation in evaluating and developing players at the most important position on the field."
Then he worked with Tom Shaw last offseason-
https://sports.yahoo.com/dak-prescott-works-tom-shaw-223113097.html
“'Coach Shaw talks to us all the time about turning your weaknesses into strengths, so that’s what I’ve been focusing on during the majority of the spring,' Prescott said. 'As an NFL quarterback, there is always some aspect of your game — accuracy, footwork, strength — something you can always work on to improve, so that’s been my focus.'"