Kwon Alexander wasn't perfect, but he's going to be very good

If I had to bet, I'd say that Kwon Alexander is going to be a really good NFL player. The rookie started nearly every snap of the 12 games he played as a rookie, and stood out for his sideline-to-sideline speed and his impact plays in the passing game. As we noted during the season, though, he was far from perfect: he consistently struggled to drop back deep in the passing game.

Someone, namely Pro Football Focus' Sam Monson, doesn't quite think Alexander will be all that good, though. Apparently, he wrote an in-depth takedown of the team's middle linebacker two weeks ago -- something I missed, but JoeBucsFan picked up on today. Mostly, Monson thinks Alexander missed too many tackles, and vacated his zone in coverage too often. That's something we talked about repeatedly last year, and it's a fair point, though Alexander got better at staying deep after about the midway point of the year.

Pro Football Focus is always interesting, to me. Their work collecting specific statistics is highly valuable, while their grades are constantly contested, but at least worth listening to. Detailed player breakdowns, though, aren't necessarily their strength. There's always a little too much confidence in their grading system, and a lack of self-reflection.

The issue with PFF's grading system isn't just that they don't know the necessary context to deliver accurate judgments, which is always going to be an issue for any third party evaluating any tape, but that the way they grade is fairly arbitrary. Missed tackles and biting on play action figure prominently in Alexander's low grade, but should they be treated as harshly as PFF treats them, or are these more minor problems? Do Alexander's quality plays perhaps make up for his inconsistencies? The grading system says no, but the system itself is more or less arbitrary.

Amusingly, Monson acknowledges that problem.

For all the mistakes he made, there were plenty of good plays in his rookie season too, enough that there are reasons for optimism looking forward. Only seven inside linebackers had more +1 graded plays than Alexander this past season, and he had six more than the nearest rookie, Anthony.

In this area, Alexander differentiates himself from other poorly graded young linebackers. Manti Te'o has never quite lived up to his expectations in San Diego, with poor grades in two of his first three seasons and one that closely matches Alexander's in 2015, but Te'o never made the volume of positive impact plays that Alexander has to demonstrate the potential for improvement. Even in 2015, Alexander more than doubled the number of +1 or better grades of Te'o, who had two years in the league to learn and grow before the season began.

Rookies make mental mistakes. That is to be expected, to a certain extent. There's a reason why the Bucs have rarely given defensive rookies as much playing time as they did Alexander.  It seems to me that PFF's grade is far too harsh for Alexander's play, even if we ignore that he is a rookie, but it is at least defensible: mistakes and missed tackles are bad, and they shouldn't be whitewashed. At the same time, we would also expect the number of missed tackles and the number of mental mistakes to decline heavily going forward.

In all, the fact is that Alexander was good and very promising, for a rookie. He wasn't perfect, but he showed enough to be very optimistic about his play going forward.