Ewing Theory and the Celtics

[obnoxiousmime]

The Ewing theory was actually a real-world occurrence of Braess' Paradox.

Braess' Paradox is a phenomena in networks where adding additional pathways does not always result in increased efficiency.   It is most famously observed in traffic, where the addition of an alternate route between points A and B can actually end up slowing things down.  It has applications in all kinds of places, from electrical and data circuits to hydraulics, plumbing to various human interaction systems.

Some researchers a while back heard about Simmons & Lowe's theory regarding Ewing and they did an analysis, looking at the scoring efficiency of Ewing and his teammates and showed that what was going on was an instance of Braess' paradox.   The short version is that while Ewing represented an efficient 'alternate route' to scoring, the distribution of shots changing when he was on/off the floor decreased the overall throughput.

In the case of the Boston Celtics, though, if Braess' Paradox is in play, it's a more nuanced thing than with what happened in the Ewing case.   With the Celtics, the problem can be broken down into three states that cover everything:

A) Possessions with Kyrie on the floor.
B) Possessions without Kyrie, in games Kyrie did not play.
C) Possessions without Kyrie, in games Kyrie started.

The team's net rating in (A) and (B) were both very, very good.

The team's net rating in (C), however, sucked like smelly things in your septic tank.   And that's the part that killed us.

That's the mystery of this entire last season and indeed, for the entire two seasons Kyrie was here.   For whatever reason, this team just could not figure out how to play well in games Kyrie started, once he would go to the bench.   The same non-Kyrie players would play great in games he did not start.

If that can be explained by Braess' Paradox, I'd be very interested.

Hmmm... I had never heard of Braess' Paradox but I will look into it more tomorrow. Very interesting!

There's also the famous "Bras Paradox." The more force used to undo one, the tighter it becomes.

[Birdman]

Irving did not fit on this team off and on the court

[Spilling Green Dye]

The Ewing theory was actually a real-world occurrence of Braess' Paradox.

Braess' Paradox is a phenomena in networks where adding additional pathways does not always result in increased efficiency.   It is most famously observed in traffic, where the addition of an alternate route between points A and B can actually end up slowing things down.  It has applications in all kinds of places, from electrical and data circuits to hydraulics, plumbing to various human interaction systems.

Some researchers a while back heard about Simmons & Lowe's theory regarding Ewing and they did an analysis, looking at the scoring efficiency of Ewing and his teammates and showed that what was going on was an instance of Braess' paradox.   The short version is that while Ewing represented an efficient 'alternate route' to scoring, the distribution of shots changing when he was on/off the floor decreased the overall throughput.

In the case of the Boston Celtics, though, if Braess' Paradox is in play, it's a more nuanced thing than with what happened in the Ewing case.   With the Celtics, the problem can be broken down into three states that cover everything:

A) Possessions with Kyrie on the floor.
B) Possessions without Kyrie, in games Kyrie did not play.
C) Possessions without Kyrie, in games Kyrie started.

The team's net rating in (A) and (B) were both very, very good.

The team's net rating in (C), however, sucked like smelly things in your septic tank.   And that's the part that killed us.

That's the mystery of this entire last season and indeed, for the entire two seasons Kyrie was here.   For whatever reason, this team just could not figure out how to play well in games Kyrie started, once he would go to the bench.   The same non-Kyrie players would play great in games he did not start.

If that can be explained by Braess' Paradox, I'd be very interested.

TP, this is really insightful and well thought out.  Provided that the team plays well with Kemba, 'C' will hopefully lead to an overall improvement in the team.

[Ogaju]

The Ewing theory was actually a real-world occurrence of Braess' Paradox.

Braess' Paradox is a phenomena in networks where adding additional pathways does not always result in increased efficiency.   It is most famously observed in traffic, where the addition of an alternate route between points A and B can actually end up slowing things down.  It has applications in all kinds of places, from electrical and data circuits to hydraulics, plumbing to various human interaction systems.

Some researchers a while back heard about Simmons & Lowe's theory regarding Ewing and they did an analysis, looking at the scoring efficiency of Ewing and his teammates and showed that what was going on was an instance of Braess' paradox.   The short version is that while Ewing represented an efficient 'alternate route' to scoring, the distribution of shots changing when he was on/off the floor decreased the overall throughput.

In the case of the Boston Celtics, though, if Braess' Paradox is in play, it's a more nuanced thing than with what happened in the Ewing case.   With the Celtics, the problem can be broken down into three states that cover everything:

A) Possessions with Kyrie on the floor.
B) Possessions without Kyrie, in games Kyrie did not play.
C) Possessions without Kyrie, in games Kyrie started.

The team's net rating in (A) and (B) were both very, very good.

The team's net rating in (C), however, sucked like smelly things in your septic tank.   And that's the part that killed us.

That's the mystery of this entire last season and indeed, for the entire two seasons Kyrie was here.   For whatever reason, this team just could not figure out how to play well in games Kyrie started, once he would go to the bench.   The same non-Kyrie players would play great in games he did not start.

If that can be explained by Braess' Paradox, I'd be very interested.

People will probably shrug when I say this, but I actually believe this may have something to do with the significant disparity in Terry Rozier's production as a starter versus a bench player.

If you look over just his last two seasons, 17-18 and 18-19, Rozier's Per-36 production over that two year stretch was as follows:

As a Starter: 16.3 Pts, 6.6 Reb, 5.7 Ast, 1.6 Stl, 1.5 TO, 42% FG, 40% 3PT, 80% FT
As a Reserve: 14.6 Pts, 6.3 Reb, 3.9 Ast, 0.8 Stl, 1.0 TO, 39% FG, 36% 3PT, 77% FT

His net ratings for last season:
2018-19 (starter): Off Rating 118, Def Rating 107, Net Rating +11
2018-19 (reserve): Off Rating 100, Def Rating 109, Net Rating -9

The only stats that didn't get significant improvements when he started (versus off the bench) were rebounding (about the same) and turnovers (which increased.  Other then that he put up better stats across the board in the games he started. 

And there are roughly 60 total games started by Rozier over those two seasons, so the sample size is pretty decent.

The two stats that really jump out at me are the Offensive Rating (which rises from 100 to 118) and assists (from 3.9 to 5.7). This gives me the impression that Rozier for some reason did a much better job of running the offense when he in the starting 5. 

Possible that when he played with that starters because of the talent around him he played more of a playmaking role, while when he came off the bench because there was a comparative lack of talent he went into ISO mode and played much less efficiently.  Or maybe it was because the lack of talent on the second unit allowed defenses to focus more of their attention on Rozier, reducing his efficiency.

Either way that Net Rating disparity is huge, and considering that Rozier was typically the guy who would come in when Kyrie sits, it may well go some way to explaining why Scenario C was such a drastic change.  The Celtics played great when Kyrie was in with the starters, and they played great when Rozier was in with the starters - but they played terrible when Rozier was on with second unit guys.

sounds like Kyrie should have been coming off the bench for the good of the team, but Coaches never coach out of the box.

[KG Living Legend]

Does Ewing Theory apply when you lose your two best players?

 Two best players lol, don't think so

[gouki88]

Does Ewing Theory apply when you lose your two best players?

 Two best players lol, don't think so

Huh? Horford and Kyrie were pretty obviously our two best last season

[Muzzy66]

We can whine and **** all we want about losing Horford, but with at contract, no way in hell should we have matched it or done better.  Philly will regret that contract for years.  Yes, Horford's a very good player and I liked him a LOT.  But not for $109M freaking dollars for 4 freaking years when he's what?  33?  Are you kidding me?

I expect this years team to be better and more fun to watch.  Even though we lost our "2 best players".

I'm curious as to what criteria are you using to measure whether or not Philly will regret the contract?  Do they need to win a title?  Or does a Finals appearance alone make it worth it?

I'm not saying the Celtics should have paid Horford, but I also don't believe Philly will regret the deal if they make a Finals appearance.  That team is in dire need of a playoff breakthrough, even if it means overpaying a broken down Horford towards the end of his contract.

Horford should also serve as an excellent mentor for Embiid.   

Horford is not exactly broken down, he hasnt had a lot of health issues in his career actually

You're absolutely right.  That's why I added "towards the end of his contract".  The point being that Philly wont view Horford as an overpay if they make an NBA Finals appearance, regardless of whether or not Horford breaks down.

As for my opinion, I think he will age in a similar fashion to Tim Duncan from this point forward.  I'm not suggesting he will have the same overall impact, but I wouldn't be surprised to see Horford as a very effective player in his mid-late 30's.  More than anything, his games played and minutes will need to be managed.

Unlikely. 

While Duncan and Horford have one thing in common (the fact that they are 'funadmental" types) they also have one very huge disparity - Duncan was 7'0" tall with a 7'5" wingspan.  He was an exceptionally long player.  And while he had a very good midrange jumper, he was most dominant in the paint where he was an elite post scorer and an elite interior defender.  It's much easier to retain those two abilities with age when you taller and longer then everybody you come up against - you don't need to move quickly to shoot over somebody.

Horford by comparison is 6'10" with a 7'0" wingspan - he has height, length and reach that aren't much grater then Jayson Tatum.  By traditional big standards, he is borderline undersized.  By today's NBA standards he's not undersized, but is far from "big".

He's still a very skilled finisher around the basket, but because of his lack of length and degrading athelticism he already struggles to get his shot off in the paint again't longer and more athletic bigs.  This has forced Horford to change his game from being an inside/out guy, to a guy who is now predominantly a jump shooter.  This will only become more obvious as he continues to age.  As his interior game further drops off teams will no longer need to respect his post game, and his ability to make plays as a passer in the post will also probably become much less relevant.

Defensively Horford has remained very good, and a big reason for that even though he isn't as big as some guys out there, he's generally been pretty mobile and fairly quick on his feet.  This has allowed him to remain a very good team defender because he has the mobility to be able to run out and challenge shooters on the perimeter, and also has the mobility to be able to switch on to quicker wing players defensively in the P&R (he's done great work on Lebron and Giannis, for example).  This ability is already showing signs of degradation the last couple of years as Horford's footspeed has slowed. 

He will remain a solid interior defender based on his physical strength and IQ alone, but when his athleticism drops to the point where he can no longer run out to contest perimeter shooters and switch effectively in the P&R, his defensive impact will reduce quite significantly. 

As Horford gets to age 36/37 in the final two years of that deal, I can see him becoming a pretty limited big man who can only really defend the paint and make make open spot up jumpers - and at that point he will probably be out there for at most 15 - 20 minutes a night while making well over $25M a year.

I think a very good Horford comparison would be David West.  He remained a starting caliber player up until about the age of 34, and after that point he was pretty much washed up, playing 15-18 minutes a night off the bench.

[wiley]

Does Ewing Theory apply when you lose your two best players?

 Two best players lol, don't think so

Huh? Horford and Kyrie were pretty obviously our two best last season

I read it that he was responding in the negative to hpantazo's question.  Not that he was refuting who the best two players were.  But you might have picked the right meaning.  We shall see...   

[KG Living Legend]

Does Ewing Theory apply when you lose your two best players?

 Two best players lol, don't think so

Huh? Horford and Kyrie were pretty obviously our two best last season

 Anybody after watching last season that thinks Kyrie is better than Tatum or Brown not paying attention IMO.

 

[obnoxiousmime]

Does Ewing Theory apply when you lose your two best players?

 Two best players lol, don't think so

Huh? Horford and Kyrie were pretty obviously our two best last season

 Anybody after watching last season that thinks Kyrie is better than Tatum or Brown not paying attention IMO.

I know things didn't end well with Irving last season, but come on.

[JSD]

I love Bill Simmons. His Podcast goes to the top of my list the moment it drops.


He lurks on these forums, hasn’t posted in nearly a year or so though.

[Green-18]

We can whine and **** all we want about losing Horford, but with at contract, no way in hell should we have matched it or done better.  Philly will regret that contract for years.  Yes, Horford's a very good player and I liked him a LOT.  But not for $109M freaking dollars for 4 freaking years when he's what?  33?  Are you kidding me?

I expect this years team to be better and more fun to watch.  Even though we lost our "2 best players".

I'm curious as to what criteria are you using to measure whether or not Philly will regret the contract?  Do they need to win a title?  Or does a Finals appearance alone make it worth it?

I'm not saying the Celtics should have paid Horford, but I also don't believe Philly will regret the deal if they make a Finals appearance.  That team is in dire need of a playoff breakthrough, even if it means overpaying a broken down Horford towards the end of his contract.

Horford should also serve as an excellent mentor for Embiid.   

Horford is not exactly broken down, he hasnt had a lot of health issues in his career actually

You're absolutely right.  That's why I added "towards the end of his contract".  The point being that Philly wont view Horford as an overpay if they make an NBA Finals appearance, regardless of whether or not Horford breaks down.

As for my opinion, I think he will age in a similar fashion to Tim Duncan from this point forward.  I'm not suggesting he will have the same overall impact, but I wouldn't be surprised to see Horford as a very effective player in his mid-late 30's.  More than anything, his games played and minutes will need to be managed.

Unlikely. 

While Duncan and Horford have one thing in common (the fact that they are 'funadmental" types) they also have one very huge disparity - Duncan was 7'0" tall with a 7'5" wingspan.  He was an exceptionally long player.  And while he had a very good midrange jumper, he was most dominant in the paint where he was an elite post scorer and an elite interior defender.  It's much easier to retain those two abilities with age when you taller and longer then everybody you come up against - you don't need to move quickly to shoot over somebody.

Horford by comparison is 6'10" with a 7'0" wingspan - he has height, length and reach that aren't much grater then Jayson Tatum.  By traditional big standards, he is borderline undersized.  By today's NBA standards he's not undersized, but is far from "big".

He's still a very skilled finisher around the basket, but because of his lack of length and degrading athelticism he already struggles to get his shot off in the paint again't longer and more athletic bigs.  This has forced Horford to change his game from being an inside/out guy, to a guy who is now predominantly a jump shooter.  This will only become more obvious as he continues to age.  As his interior game further drops off teams will no longer need to respect his post game, and his ability to make plays as a passer in the post will also probably become much less relevant.

Defensively Horford has remained very good, and a big reason for that even though he isn't as big as some guys out there, he's generally been pretty mobile and fairly quick on his feet.  This has allowed him to remain a very good team defender because he has the mobility to be able to run out and challenge shooters on the perimeter, and also has the mobility to be able to switch on to quicker wing players defensively in the P&R (he's done great work on Lebron and Giannis, for example).  This ability is already showing signs of degradation the last couple of years as Horford's footspeed has slowed. 

He will remain a solid interior defender based on his physical strength and IQ alone, but when his athleticism drops to the point where he can no longer run out to contest perimeter shooters and switch effectively in the P&R, his defensive impact will reduce quite significantly. 

As Horford gets to age 36/37 in the final two years of that deal, I can see him becoming a pretty limited big man who can only really defend the paint and make make open spot up jumpers - and at that point he will probably be out there for at most 15 - 20 minutes a night while making well over $25M a year.

I think a very good Horford comparison would be David West.  He remained a starting caliber player up until about the age of 34, and after that point he was pretty much washed up, playing 15-18 minutes a night off the bench.

All fair points.  You're analysis pretty much justifies his move to Philly, as I believe you're largest concerns would have become more of a reality if he had stayed in Boston.  Al strikes me as a player who will take excellent care of his body, so I'm expecting him to be an impactful player towards the end of the contract. 

His increasingly perimeter oriented game wont be a problem if he's still playing with Simmons and Embiid.  I'm also not expecting a steep athletic decline unless his suffers a major injury.  You're likely correct about his minutes dropping into the high teens towards the end of the contract, at least in the regular season.  That said, I wouldn't be surprised if he can still dial it up for 25 minutes in important playoff games.

Obviously I can't be certain about how motivated Al will be in a few years, but modern science and training should give him every opportunity to retain his effectiveness for the duration of the contract.

[pablohoney]

https://www.basketball-reference.com/teams/BOS/2019/on-off/

When Horford was on the court, our team had a +6.1 net rating.  When Horford was off the court, our team had a +3.7 net rating.  So we were +2.4 points better per 100 possessions when he played.  If we were better without him, I think that would have shown up.

Other celtics net ratings last season:
Tatum +4.6
Theis +4.5
Baynes +3.9
Semi +3.6
Kyrie +3.3
Smart EVEN
Hayward EVEN
Jaylen -3.7
Marcus Morris -5.1
Rozier -9.4

Interestingly, our team was always a net positive with any single one of our rotation players off the court which speaks to how our team never overly relied on any one player.  The player our team fared the worst with on the bench was Tatum (+1.9).

In 2017-18, Celtics were a +7.2 with Horford in the game and a -1.0 when he was on the bench.  He was second on the team in net differential (+8.2) with, once again, Tatum #1 on the team (+8.5).  Jaylen was tied with Horford with a +8.2 that season.

Great post.  Let’s call it the Tatum theory.  Our team will be better because if our best player Tatum will gets the rock as often as he merits.