Jaylen Brown is passing all the tests for the Boston Celtics this season

In his second season, Jaylen Brown has taken the leap from bit-part rookie, who was in and out of the rotation, to a key cog in the Boston Celtics machine.

We, as fans, or analysts, often talk about the eye test. Does this guy pass the eye test, or does another guy pass the eye test. Basically, what we’re asking; is there anything the stats aren’t telling us? Is there an element of a players game you need to see in order to fully appreciate them?

Brown’s teammate, Marcus Smart, is an eye-test player. We have to watch him to understand what he does for this team that may not show up in box scores.

Back to Brown. What he’s doing in this system, in his second year, is remarkable. It may be small sample sizes, but he has made a jump and should be commended.

According to basketball-reference, Brown has increased his counting stat averages everywhere other than assists. Counting stats are points, rebounds, assists, blocks, and steals. Rookie year to sophomore year increases are to be expected, but he’s doing it with an increased usage, up roughly three percent. Encouragingly, his turnover percent is down, even with the increase in usage.

Digging into the numbers, Brown’s defensive rating, or points allowed per 100 possessions, is down to 98 from 110 last season. Much was made over the Celtics losing Jae Crowder and Avery Bradley in the offseason; they were considered their best perimeter defenders last season. Brown has stepped in wonderfully.

Offensively, his rating is up five points. I’d say, so far, this offense has yet to click. Boston currently ranks 18th in offensive rating per basketball-reference. The talent is there, there’s no way Boston remains a bottom half offensive team. Which means, expect an increase in his offensive rating.

Lastly, Brown’s PER, or player efficiency rating, is up to 15.2 from 10.3. Which, according to ESPN, is about league average.

The thing about Brown is when you watch him play, you can see what he’s doing for this team. His stats back up the eye test. Most of what you see comes on the defensive end. Brown is a hyper-athletic 2 guard. He stands at 6’7″, has a wingspan of 7′, and a standing reach of 8’6″, according to Draft Express.

Brown’s versatility, and switch-ability, across three or four positions is essential to this defensive scheme. He can comfortably guard opposing players two through four with his size, and has the athleticism to take on some opposing point guards.

All you have to do is watch Brown to see his activity on the defensive end. Additionally, he’s a leaper, so his blocks, and steals stand out even more. He’s managing to turn his defense into offense. A valuable skill for any 3 and D stopper.

Offensively, we’re starting to see Brown’s impact, too. Since Hayward went down, he has come up time and again in big moments. The Warriors game was just one example, but it was in perhaps the biggest game of the year.

Brown has made himself indispensable on the current Celtics roster. Fans can see how hard he’s working, and analysts can back that up. It isn’t often second year dudes can pass the eye test, and the stats test, especially on the best team in the conference.