The problem that Trey has is that given the 24/7/365 nature of sports, most athletes have done their 10,000 hours prior to reaching the NFL. That or they have exceptional talent - enter Trey Lance and Shanahan.
Anyway, Lance looks like a guy with incredible physical talent that is still putting in his 10,000 hours and so some of the movements natural to a QB seem robotish and mechanical to him...because they are. It's very hard to teach someone at his age in real game-time situations without ruining his confidence. So while practice reps are invaluable for him, the thing that is working against Trey Lance is time...time in real games. I mean, they are still working on his footwork, reads, etc...which means he looks exactly as he should look ...probably leaning towards the more positive side after the Raider game. But he'll only be "young" and "developmental" for another 18 months if he's lucky...after that..."bust".
