By Greg Gabriel–

Editor’s note: You can read Gabriel’s other scouting reports on highly regarded NFL Draft prospects by clicking here.

(CBS) When you partake in the process of evaluating quarterbacks, you can’t just look at a few games and say that you know the player. You have to look closely at the whole body of work at such a critical position.

As it pertains to Notre Dame quarterback DeShone Kizer, that means looking at both 2015 and 2016 tape.

The 21-year-old Kizer has ideal NFL size for the quarterback position. At the NFL Combine, he will measure close to6-foot-4 and 230 pounds, and I would estimate he will run in the 4.70 range. He’s big, strong and athletic. While he doesn’t have the quick athleticism of, say, a Russell Wilson, he will most likely test better than Jameis Winston, who has similar size.

Kizer has a really strong arm and can easily throw the ball 60 yards down field. He shows outstanding velocity on short- to mid-range throws. Put simply, he can make all the throws a a top NFL quarterback is asked to do.

He also has the athleticism to extend plays with his feet or just be a runner. He had a number of long runs in his Notre Dame career and, when he wants, can be a punishing runner with his size and power.

When you look at Kizer’s mechanics, he holds the ball high and has a quick overhand delivery. When he makes a decision, the ball is out of his hand quickly.

The spread offense that Kizer played in at Notre Dame is more sophisticated than many of the spread offenses we see elsewhere at the collegiate level. The Notre Dame offense is a whole-field read scheme in which the quarterback has to go through a progression that encompasses both sides of the field. He also can change the play and/or protections at the line of scrimmage. Given all that, Kizer was asked to do more than many spread quarterbacks are asked to do.

When you look at 2015 tape, Kizer made some really impressive throws, both short and deep, and was productive. He threw for for 2,884 yards and 21 scores with 10 interceptions in 2015. He also rushed 520 yards.

One key was that Kizer was playing behind a veteran offensive line, two members of which were high draft picks a year ago. He also had a veteran receiving corps.

For instance, we saw many quick slant throws in 2015 that we seldom saw in 2016. He also was much more accurate on his deep throws in 2015. In fact, one general manager told me after the 2015 season that Kizer was a Super Bowl-type quarterback and could start for his team right away.

Much of that changed in 2016. There was the unnecessary quarterback controversy at Notre Dame, and the offensive line wasn’t as experienced or as talented and the receivers were mostly first-year starters.

The controversy was brought about because going into the 2015 season, Malik Zaire was the starter. He broke his ankle in the second game, and Kizer took over from there. The issue stemmed from Irish coach Brian Kelly not knowing what he had in Kizer initially, so he told Zaire after the injury that he would be the starter in 2016, when he’d be back to full health.

Kelly found out in quick order that he had someone special in Kizer, but he couldn’t go back on his word. And thus the ensuing dilemma, one in which the two quarterbacks would split series in the season opener. Kizer ended up outperforming Zaire and was given the starting job, but the damage was done. I believe he felt he was always looking over his shoulder and that the early approach hurt his confidence and thus overall play in 2016.

Kizer was also playing with a far less experienced group of players, and his play fell off. Throws that he had made easily in 2015, he wasn’t making in 2016. With a horrible defense, Notre Dame either had to play catch-up or always score in order to stay in a game, which led to similar final stat line despite his play dropping off.

I have no doubt that Kizer is the most talented quarterback in this draft class. Circumstances beyond his control led to him not having the 2016 season that many envisioned. Are there areas he needs to improve in? Certainly, but that’s the case with every quarterback. Kizer too often tries to make the big play instead of taking what’s there, and that can lead to costly turnovers.

Still, when you look at the big picture and his physical traits, he compares quite favorably to the other top quarterbacks.

The final quarterback rankings will be determined over the next eight weeks as teams put the top prospects through private workouts and meetings, which will tell decision-makers a lot. I expect Kizer to perform well.

Will Kizer be the first or second quarterback drafted? That remains to be seen at this time, but I have no doubt that the team that selects him will be hitting a home run.

Greg Gabriel is a former NFL talent evaluator who is an on-air contributor for 670 The Score. Follow him on Twitter @greggabe.