What is going on with Jaylen Brown's role?

[bdm860]

My personal opinion: for Stevens all mistakes aren't equal and defensive mistakes are the worst mistakes you can make.

With all mistakes not being equal, the biggest complaints for guys like Morris and Rozier from the fans seems to be their shot selection.  I think this bothers Stevens the least.  Also getting scored on or getting caught in a pick and roll or getting beat on a rotation, etc. doesn't seem to be as big of a sin as just flat out making the wrong defensive play.  Just my personal opinion of how Stevens thinks.  Also maybe he expects more from Brown so he's harder on him?

While Brown's a good 1-on-1 defender, I think he makes a lot of mistakes from a help/team defensive perspective.  Started noticing this when I asked the same question a few games ago.  And now I specifically see things like this from Brown now that I'm watching closely for them (but to be fair, not watching others with the same microscope, also there's a lot of plays where Brown plays stellar D as well):

....deleted stuff ...

I think if we were to go back and look at games where Brown doesn't play a lot of minutes, you'll see a lot of plays like these.  These are the plays that get him yanked by Stevens.  Do others make as many mistakes or as grievous of mistakes? I don't know.  But this is what I think keeps Brown from getting more minutes.

You can anecdotally find defensive mess-ups by any player you want if you go back and search for them.  Even guys like Al Horford make the occasional goof.

Since January 1, the team's defensive rating with Jaylen on the floor is 107.9 points per 100 possessions.   With Jaylen on the bench it has been a horrific 120.7.  That's a gigantic 12.8 point difference!

For comparison, the team defense has been 2.5 points worse with Morris on the floor as opposed to off.

That suggests that, in the aggregate, maybe Jaylen isn't anywhere close to the defensive screw-up that an anecdotal selection of plays would portray?

On an individual level, Jaylen is currently second on the team in shot contention, causing opponent's to shoot at a -3.5 differential FG%.  That's on 9.3 DFGA per game, which is a lot considering his minutes are significantly less than a full time starter.  That's reflective of the fact that he's often tasked with guarding one of the other team's better scorers.   He's third on the team in Defensive Win Shares per 48.

If Brad really is dinging Jaylen's minutes based on the occasional defensive mistake, without really understanding the overall aggregate impact on the team defense, then he's ... perhaps not as smart as many would like to think?

The only problem is your using a stat that NBA teams don't use (d rating).

Daryl Morey has gone on record saying there's no publicly available stat that indicates if somebody is a good defender.

Danny Ainge has also publicaly stated he doesn't even look at Defensive Rating stats (I can try to pull a clip for you in the morning if you need proof).

When 2 of the GM's widely considered to be the best in the game don't use a stat, that should tell you something about that stat.

I don't think the team not understanding impact is something that's happening here.

[droopdog7]

Looking from the outside, I would guess that Stevens simply doesn’t trust brown.  He’s capable of some really good AND really dumb things. 

[Somebody]

Looking from the outside, I would guess that Stevens simply doesn’t trust brown.  He’s capable of some really good AND really dumb things.

Which is kind of the case with Rozier, Morris and Tatum. Don't see why he'd freeze the player who's looking like the best young talent on our team right now.

[Triplenickle]

They wouldn't have all these goofy mismatch mistakes and players not getting playing time for it if they didn't use that ineffective silliness in the first place.

The end.

They can never play on instinct and reflex because they're constantly trying to be in sync like they're playing female water gymnastics or some mess.

[keevsnick]

My personal opinion: for Stevens all mistakes aren't equal and defensive mistakes are the worst mistakes you can make.

With all mistakes not being equal, the biggest complaints for guys like Morris and Rozier from the fans seems to be their shot selection.  I think this bothers Stevens the least.  Also getting scored on or getting caught in a pick and roll or getting beat on a rotation, etc. doesn't seem to be as big of a sin as just flat out making the wrong defensive play.  Just my personal opinion of how Stevens thinks.  Also maybe he expects more from Brown so he's harder on him?

While Brown's a good 1-on-1 defender, I think he makes a lot of mistakes from a help/team defensive perspective.  Started noticing this when I asked the same question a few games ago.  And now I specifically see things like this from Brown now that I'm watching closely for them (but to be fair, not watching others with the same microscope, also there's a lot of plays where Brown plays stellar D as well):

....deleted stuff ...

I think if we were to go back and look at games where Brown doesn't play a lot of minutes, you'll see a lot of plays like these.  These are the plays that get him yanked by Stevens.  Do others make as many mistakes or as grievous of mistakes? I don't know.  But this is what I think keeps Brown from getting more minutes.

You can anecdotally find defensive mess-ups by any player you want if you go back and search for them.  Even guys like Al Horford make the occasional goof.

Since January 1, the team's defensive rating with Jaylen on the floor is 107.9 points per 100 possessions.   With Jaylen on the bench it has been a horrific 120.7.  That's a gigantic 12.8 point difference!

For comparison, the team defense has been 2.5 points worse with Morris on the floor as opposed to off.

That suggests that, in the aggregate, maybe Jaylen isn't anywhere close to the defensive screw-up that an anecdotal selection of plays would portray?

On an individual level, Jaylen is currently second on the team in shot contention, causing opponent's to shoot at a -3.5 differential FG%.  That's on 9.3 DFGA per game, which is a lot considering his minutes are significantly less than a full time starter.  That's reflective of the fact that he's often tasked with guarding one of the other team's better scorers.   He's third on the team in Defensive Win Shares per 48.

If Brad really is dinging Jaylen's minutes based on the occasional defensive mistake, without really understanding the overall aggregate impact on the team defense, then he's ... perhaps not as smart as many would like to think?

The only problem is your using a stat that NBA teams don't use (d rating).

Daryl Morey has gone on record saying there's no publicly available stat that indicates if somebody is a good defender.

Danny Ainge has also publicaly stated he doesn't even look at Defensive Rating stats (I can try to pull a clip for you in the morning if you need proof).

When 2 of the GM's widely considered to be the best in the game don't use a stat, that should tell you something about that stat.

I don't think the team not understanding impact is something that's happening here.

You are right that no stat really sums up how god a defender is, but you are wrong in terms if how defensive rating stats are viewed. Rating stats are routinely cited as some of the most important analytical tools when attempting to decipher a players impact. What Ainge and Morey are really saying is that ratings stars are complicated because they are to some extent based on who else shares the floor with you. But in the event these stats are extreme or match the eye test they can give you a pretty good idea of whether somebody is having a positive defensive impact. I have found or seen no real argument to suggest that Jaylen Brown isnt a good, and significantly better than Morris level defender. 

[td450]

Looking from the outside, I would guess that Stevens simply doesn’t trust brown.  He’s capable of some really good AND really dumb things.

Which is kind of the case with Rozier, Morris and Tatum. Don't see why he'd freeze the player who's looking like the best young talent on our team right now.

Let me give you an example:

When we played Portland at the end of February, at the end of the third quarter, we scored with about 7 seconds to go. The game was starting to get away from the C's and they needed to turn up the effort. Lilliard got the ball out of bounds, and Smart was a few steps ahead of him.

Lilliard just ran right by Smart. No pick, no crazy crossover. Just ran right by him. Smart appeared to be distracted, and just didn't react quickly enough. Horford, another great defender, also reacted too late, even though it was easy enough to see him coming, and Lilliard blew past him at the top of the key with almost zero resistance.

Lilliard scored on an uncontested layup with less than a second to go. Portland wanted it more and went on to win by 5.

Everyone in the NBA blows it sometimes, and if you want to, you can see anyone as dumb. The only reasonable standard is overall impact, and by that measure, Jaylen is a very good defender.