The three main aspects that Jacoby Brissett needs to improve on are all pocket fundamentals.... progression reading, anticipation, and timing. This is very typical for inexperienced quarterbacks. These are the things that I need to see him improve on as a Senior. He must get better from inside the pocket. In order to accomplish this, he has to remain in the pocket.
A lot of his success is on half field reads from a designed sprint-out, or bailing the pocket to extend the play with his legs if his first read isn't open. He's not very comfortable staying in the pocket yet, and it causes him to bail on his progressions in the process. This is why his YPA is so low for his career at 6.4. Brissett has to develope a better profile from within the confines of the pocket as he gains experience. Working through his progressions will allow him to develope better timing, and facilitate throwing with anticipation. It's a process. It'll eliminate his tendancy to hold on to the football too long and take unnecessary sacks from inside the pocket. I think he should conquer most of this as a Senior in 2015 as he furthers his development and gains more experience.
In other words, when I look at his weaknesses compared to the weaknesses of other Senior quarterbacks with similar physical ability, like Dak Prescott for example, I like Brissett's weaknesses better. Prescott has intangibles and leadership qualites that elevate an entire program. However, in terms of projecting them to the NFL as passers, Prescott's decision making is still troublesome at times. Decision making and protecting the football is one of the biggest improvements Brissett has made thusfar in his development after transferring from Florida. The next step in the process is the pocket fundamentals that I've detailed here. If he does that, he could move as high as #2 or #3 on my list of Senior quarterbacks. All I have to do is see it first.