Kizer declared after a tumultuous 2nd starting season at South Bend. But it's hard to second guess that decision as it seemed his HC was not always in his corner last year.
Kizer’s young (just turned 21) and checks the boxes on his physical skill set. Big arm, good stature/size, mobility and running ability. He routinely makes NFL caliber throws into tight spaces. As a RS fresh stepping in for an injured Zaire, he showed good poise. In fact, it was the aspect I liked most about his game. That season he helped ND win games and was clutch.
Unfortunately he lost a lot of that mojo this year. His poise failed him too many times. He was wildly inaccurate. He lost the confidence of his HC. And his confidence seemed to take a major hit. Though he played behind one of the better OLs in college, he simply wasn't as effective this year with some of his key weapons missing. ND plays a pro style scheme but Kizer doesn't regularly make full field reads. He's generally a one read lock on thrower.
He's a high upside developmental QB. His confidence will need an intervention after a difficult college season. Long term starter traits are clearly there if he can improve his consistency and poise as a pro but I wouldn't want to take him before the 3rd round. He might end up similar to Auburn Jason Campbell. JC had all the traits... arm, mobility, leadership.. but was just too inconsistent as a long term starter.
Pro Comparison: Jason Campbell