Well, the jump in his completion percentage is due simply to throwing much shorter passes this year. His passes on average are traveling 3+ yards/attempt shorter this season. He still struggles a lot with down field accuracy.
His accuracy against opponents from BCS conferences last year dropped off even further to around 46%. Get him in obvious passing situations like a 3rd and 7, and it dropped even further down to around 30%.
He's throwing more arrow routes to the flat this year which is inflating his completion percentage. He's still holding the ball too long on deeper developing routes. He doesn't throw with anticipation in other words. He's completing a high percentage of his passes this season to the first thing of his own color that outflanks the defense off the zone read.
Hill is still BYU's best running back. That's why I still consider him in the athlete category. However, there are other QB's like Everett Golson that have made significantly more strides as a passer than Taysom Hill has. Golson looks so much different in the pocket now after working with George Whitfield, I can't believe I'm watching the same player from 2012. His improvement is immense. Very impressive.
Now that it sounds like I've only had criticism for Taysom Hill, let me explain why I put him here in the first place...
I absolutely love this kid's running ability. He does run with the same toughness and intensity of a legendary player like Tim Tebow. He has the ability to completely dominate any game as a runner. Nearly the size of Tebow, but faster.
He won't win the Heisman because they won't play anybody. They don't have the schedule to make him a legitimate threat for it. I don't see how anyone could have him at #2 at the moment...he's played UCONN, Texas, and Houston tonight. Mariota has already beaten Michigan St. and Gurley has dominated Clemson already. There's your top 2 as it stands in reality. And many more ranked teams to come for both.
Taysom Hill has a significant amount of developing to do as a passer. He's a mid-round prospect at best right now if you're intent on developing him as a legitimate next level signal caller in my opinion.
Had the exact same reaction watching Golson. Couldn't believe it.