Author Topic: Offensive rebounding over getting back on D increases net production [Analytics]  (Read 7374 times)

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Offline LB3533

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If we had Russell anchoring the paint on opponents' fastbreaks, I'd have my guys offensive rebound like no tomorrow.

Offline CelticConcourse

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If we had Russell anchoring the paint on opponents' fastbreaks, I'd have my guys offensive rebound like no tomorrow.

Irrelevant much? ;D Last I checked, Russell isn't on our active roster. Did we send him to the D-League?
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Offline guava_wrench

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I did not look at the paper, but as many have noted, there is an obvious problem. Coaches choose strategies due to expected outcomes for their team, not for the entire league.

Imagine a study that says that attempting to steal second is a better strategy than not attempting to steal second, so the Red Sox decide to give the green light to Ortiz every time he is on first. The stats for attempted steals are heavily skewed towards the outcomes for guys with good speed who have the best chance of success.

Similarly, the crashing the boards stats will be skewed due to good offensive rebounding teams being over-represented in the 2 people crashing category. Bad rebounding teams would be over-represented in the 2 people retreating category.

My comment might not be valid if they controlled for this. There are many ways they could do so mathematically.

Offline LooseCannon

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I did not look at the paper, but as many have noted, there is an obvious problem. Coaches choose strategies due to expected outcomes for their team, not for the entire league.

Since you did not look at the paper, in the conclusion, the authors explicitly state "Moreover, there are many factors we have yet to consider, e.g. the positioning of the defensive players, the game situation, and the especially the personnel on the floor."

This suggests that, pending the availability of data, this is likely only the first in a series of papers on this subject by the authors as they delve into the statistics.  The purpose of this paper seems to be to set up a few metrics and a theoretical framework that can be used to examine this question in greater depth in the future.
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Offline guava_wrench

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I did not look at the paper, but as many have noted, there is an obvious problem. Coaches choose strategies due to expected outcomes for their team, not for the entire league.

Since you did not look at the paper, in the conclusion, the authors explicitly state "Moreover, there are many factors we have yet to consider, e.g. the positioning of the defensive players, the game situation, and the especially the personnel on the floor."

This suggests that, pending the availability of data, this is likely only the first in a series of papers on this subject by the authors as they delve into the statistics.  The purpose of this paper seems to be to set up a few metrics and a theoretical framework that can be used to examine this question in greater depth in the future.
Pretty much the same kind of conclusion we see in 90% of published papers -- more research needed!

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Offline BballTim

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I read through it a week or so ago.  For as big of a deal as the Sloan Conference is, I was surprised by how incomplete the paper seemed.  The authors acknowledge a lot of the flaws in their study, but at this point, their analysis just doesn't tell us a lot.

This is how research works.  It's incomplete because the available data is incomplete.  Sometimes, it is necessary to do analysis that tell us that we can't know.  I think Doc has made statements in the past suggesting that the Celtics' in-house analysis (which is presumably farther along what gets publicly presented) tells him that he doesn't need to push offensive rebounding.

The study did acknowledge that there is a trade off between crashing the boards and transition defense, so one reasonable hypothesis is that the team that would benefit the least from emphasizing offensive rebounding might be a team with poor rebounders and a good half-court defense, while a team that should go for the rebound more is a team with good rebounders and offense and a poor defense that will give up points anyways even if its players get back early on defense. 

Since the quality of personnel hasn't been factored in, perhaps it will be revealed that certain types of players should go for the offensive rebound and other types of player shouldn't, or that players' tendency to crash the boards should change depending on who they are guarding.

  The problem is the study is measuring the results of what happens when teams are doing what they do (or think they do) well. That doesn't really mean that teams could change what they do and still be successful. Imagine my doing a study claiming that three point shots are much more efficient shots to take than 18 footers. The doesn't mean that Brandon Bass will improve his scoring efficiency if he starts chucking up shots 6 feet farther from the basket than he does now. While it's more efficient in terms of scoring to have players that are good 3 point shooters than players who are good mid-range shooters, it wouldn't be more efficient to just tell all your players to get behind the arc before they shoot.

Offline Snakehead

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It's an interesting analysis but the main thing they're not accounting for is that while "crashing" seems to be the better strategy on the aggregate, teams with personnel who are below-average offensive rebounders - like, I don't know, us - have a lower expected return than teams with average or above-average O rebounding personnel.  This can change the math substantially. 

I'm also curious how they calculated expected return - whether that's just a generic points per possession or if they're actually calculating expected return after offensive boards specifically.
Not to mention that Doc has shown a willingness to let good offensive rebounders crash when we've had them on the court.

Rondo is allowed to go for them, Glen Davis when he was the 4th big, Kendrick Perkins, Powe, and most recently Jared Sullinger.

We certainly don't make it a point to have two bodies on the offensive glass most times like many teams, but you have to think its somewhat talent based. (though they've also tried to get a lot of shooting bigs over the years too, ones that don't crash)

Yeah Faf is right here.  People who are critical of Doc: why did Doc let Sullinger crash in for offensive boards any time he was on the floor?  Because he's actually a great rebounder.

Basically the rest of our players are not good rebounders and are good defenders so they might as well get back.


Interesting study though, interested to see what they build off of this.  As a few have mentioned, this is how research works: you cite many sources and contribute a part.  Then hopefully someone takes you as a source and builds upon your work.

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Offline action781

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It's an interesting analysis but the main thing they're not accounting for is that while "crashing" seems to be the better strategy on the aggregate, teams with personnel who are below-average offensive rebounders - like, I don't know, us - have a lower expected return than teams with average or above-average O rebounding personnel.  This can change the math substantially. 

I'm also curious how they calculated expected return - whether that's just a generic points per possession or if they're actually calculating expected return after offensive boards specifically.
Not to mention that Doc has shown a willingness to let good offensive rebounders crash when we've had them on the court.

Rondo is allowed to go for them, Glen Davis when he was the 4th big, Kendrick Perkins, Powe, and most recently Jared Sullinger.

We certainly don't make it a point to have two bodies on the offensive glass most times like many teams, but you have to think its somewhat talent based. (though they've also tried to get a lot of shooting bigs over the years too, ones that don't crash)

Wilcox has been crashing lately, as well.

I think I remember Krstic getting 2 offensive boards in his first 2 possessions as a celtic.  Not only does he let them, but it also is a bit of a sneak attack that the opponents aren't expecting!
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Offline jdz101

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I read through it a week or so ago.  For as big of a deal as the Sloan Conference is, I was surprised by how incomplete the paper seemed.  The authors acknowledge a lot of the flaws in their study, but at this point, their analysis just doesn't tell us a lot.

This is how research works.  It's incomplete because the available data is incomplete.  Sometimes, it is necessary to do analysis that tell us that we can't know.  I think Doc has made statements in the past suggesting that the Celtics' in-house analysis (which is presumably farther along what gets publicly presented) tells him that he doesn't need to push offensive rebounding.

The study did acknowledge that there is a trade off between crashing the boards and transition defense, so one reasonable hypothesis is that the team that would benefit the least from emphasizing offensive rebounding might be a team with poor rebounders and a good half-court defense, while a team that should go for the rebound more is a team with good rebounders and offense and a poor defense that will give up points anyways even if its players get back early on defense. 

Since the quality of personnel hasn't been factored in, perhaps it will be revealed that certain types of players should go for the offensive rebound and other types of player shouldn't, or that players' tendency to crash the boards should change depending on who they are guarding.

  The problem is the study is measuring the results of what happens when teams are doing what they do (or think they do) well. That doesn't really mean that teams could change what they do and still be successful. Imagine my doing a study claiming that three point shots are much more efficient shots to take than 18 footers. The doesn't mean that Brandon Bass will improve his scoring efficiency if he starts chucking up shots 6 feet farther from the basket than he does now. While it's more efficient in terms of scoring to have players that are good 3 point shooters than players who are good mid-range shooters, it wouldn't be more efficient to just tell all your players to get behind the arc before they shoot.

I think you're over-stretching what the video/paper is trying to say. The piece never says you'll be a far better team if you send all 5 guys to crash, and fail to get back on defense. That's ludicrous. All the video is saying is that the league as a whole benefits off missed jumpshots when they send one guy to crash instead of nobody, or two guys to crash instead of one.

A study you can definitely poke plenty of holes in, but interesting fodder all the same.


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Offline BballTim

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I read through it a week or so ago.  For as big of a deal as the Sloan Conference is, I was surprised by how incomplete the paper seemed.  The authors acknowledge a lot of the flaws in their study, but at this point, their analysis just doesn't tell us a lot.

This is how research works.  It's incomplete because the available data is incomplete.  Sometimes, it is necessary to do analysis that tell us that we can't know.  I think Doc has made statements in the past suggesting that the Celtics' in-house analysis (which is presumably farther along what gets publicly presented) tells him that he doesn't need to push offensive rebounding.

The study did acknowledge that there is a trade off between crashing the boards and transition defense, so one reasonable hypothesis is that the team that would benefit the least from emphasizing offensive rebounding might be a team with poor rebounders and a good half-court defense, while a team that should go for the rebound more is a team with good rebounders and offense and a poor defense that will give up points anyways even if its players get back early on defense. 

Since the quality of personnel hasn't been factored in, perhaps it will be revealed that certain types of players should go for the offensive rebound and other types of player shouldn't, or that players' tendency to crash the boards should change depending on who they are guarding.

  The problem is the study is measuring the results of what happens when teams are doing what they do (or think they do) well. That doesn't really mean that teams could change what they do and still be successful. Imagine my doing a study claiming that three point shots are much more efficient shots to take than 18 footers. The doesn't mean that Brandon Bass will improve his scoring efficiency if he starts chucking up shots 6 feet farther from the basket than he does now. While it's more efficient in terms of scoring to have players that are good 3 point shooters than players who are good mid-range shooters, it wouldn't be more efficient to just tell all your players to get behind the arc before they shoot.

I think you're over-stretching what the video/paper is trying to say. The piece never says you'll be a far better team if you send all 5 guys to crash, and fail to get back on defense. That's ludicrous. All the video is saying is that the league as a whole benefits off missed jumpshots when they send one guy to crash instead of nobody, or two guys to crash instead of one.

A study you can definitely poke plenty of holes in, but interesting fodder all the same.

  My point was they're measuring teams playing the way they think they'll be the most successful. That doesn't mean that teams altering their play will improve their success, as they seemed to implying. The Celts might have less success sending in KG and Bass for Orebs than the Jazz might have with Al and Milsap, they might also lose more in transition defense than (for instance) the Clippers.

Offline jdz101

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I read through it a week or so ago.  For as big of a deal as the Sloan Conference is, I was surprised by how incomplete the paper seemed.  The authors acknowledge a lot of the flaws in their study, but at this point, their analysis just doesn't tell us a lot.

This is how research works.  It's incomplete because the available data is incomplete.  Sometimes, it is necessary to do analysis that tell us that we can't know.  I think Doc has made statements in the past suggesting that the Celtics' in-house analysis (which is presumably farther along what gets publicly presented) tells him that he doesn't need to push offensive rebounding.

The study did acknowledge that there is a trade off between crashing the boards and transition defense, so one reasonable hypothesis is that the team that would benefit the least from emphasizing offensive rebounding might be a team with poor rebounders and a good half-court defense, while a team that should go for the rebound more is a team with good rebounders and offense and a poor defense that will give up points anyways even if its players get back early on defense. 

Since the quality of personnel hasn't been factored in, perhaps it will be revealed that certain types of players should go for the offensive rebound and other types of player shouldn't, or that players' tendency to crash the boards should change depending on who they are guarding.

  The problem is the study is measuring the results of what happens when teams are doing what they do (or think they do) well. That doesn't really mean that teams could change what they do and still be successful. Imagine my doing a study claiming that three point shots are much more efficient shots to take than 18 footers. The doesn't mean that Brandon Bass will improve his scoring efficiency if he starts chucking up shots 6 feet farther from the basket than he does now. While it's more efficient in terms of scoring to have players that are good 3 point shooters than players who are good mid-range shooters, it wouldn't be more efficient to just tell all your players to get behind the arc before they shoot.

I think you're over-stretching what the video/paper is trying to say. The piece never says you'll be a far better team if you send all 5 guys to crash, and fail to get back on defense. That's ludicrous. All the video is saying is that the league as a whole benefits off missed jumpshots when they send one guy to crash instead of nobody, or two guys to crash instead of one.

A study you can definitely poke plenty of holes in, but interesting fodder all the same.

  My point was they're measuring teams playing the way they think they'll be the most successful. That doesn't mean that teams altering their play will improve their success, as they seemed to implying. The Celts might have less success sending in KG and Bass for Orebs than the Jazz might have with Al and Milsap, they might also lose more in transition defense than (for instance) the Clippers.

Yep, understood, and the Cs/doc rivers have obviously done their own analysis on this which they believe very strongly in.

As far as personal opinion goes I just think that zero guys trying to create a second possession or points on a rebound has to be detrimental to a team over large numbers of missed shots. I see it a lot with the celtics.

I don't care if it's Brandon Bass, Jared Sullinger or Kevin Garnett, if one celtics player goes for the offensive rebound, that doesn't necessarily mean an extra guy in transition for the opposition. That can also mean the opposition needs to send another guy to contest Brandon or Sully, and if they still beat out a couple of guys under the rim for the offensive rebound to get another shot for the celtics that can be a huge lift for the team. Intangibles are often raved about on this forum; some of my most exhilarating intangibles this year have been guys fighting multiple opposition players under the rim for a putback. Sully's beautiful putback against Camby being one memorable one.

Teams overall are getting smaller these days. They aren't exactly laden with amazing rebounders at both 4 and 5 positions these days, but they're still benefitting from offensive glass more than the celtics are.

The Knicks start Carmelo Anthony at the 4 but you try telling them that tyson chandler's tap-out rebounds to their three point shooters aren't invaluable to them on offense. Tyson chandler whilst being a good rebounder, isn't an amazing rebounder, he was shown to be far inferior to Kevin Love in this area in the Olympics. He is still part of a tap-out system that is extremely effective though.

I don't know, I guess this study has scratched the surface of something I believe would help the celtics.



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Offline More Banners

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Quicker, more athletic teams that happen to have less than stellar execution (i.e. younger teams) should probably go for the extra rebound, loose ball, steal, block, etc. because they've got a decent chance of those sorts of things paying off, and since they're young, you can't stop them from trying anyway.

Teams that are able to execute consistently at both ends in the half-court are probably better off doing that, unless it's just too easy (i.e. rebound falls in lap).

Over the grind, one hopes that the young team gets enough extra possessions from hustle to make up for their turnovers and poor execution.  The veteran team expects to get stops and baskets when needed by running their stuff, and doesn't need to take the risks.

Might the stats support something like that?

Offline kozlodoev

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I'd wager a guess these "basketball analysts" don't even understand the basic concepts of basketball.
That's just a such a great, insightful argument.
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Offline BballTim

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The Knicks start Carmelo Anthony at the 4 but you try telling them that tyson chandler's tap-out rebounds to their three point shooters aren't invaluable to them on offense. Tyson chandler whilst being a good rebounder, isn't an amazing rebounder, he was shown to be far inferior to Kevin Love in this area in the Olympics. He is still part of a tap-out system that is extremely effective though.

  Unrelated, but I despise the tap-out rebound. All I can think of when I see it is "unskilled" or "gimmicky".

Offline CelticConcourse

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The Knicks start Carmelo Anthony at the 4 but you try telling them that tyson chandler's tap-out rebounds to their three point shooters aren't invaluable to them on offense. Tyson chandler whilst being a good rebounder, isn't an amazing rebounder, he was shown to be far inferior to Kevin Love in this area in the Olympics. He is still part of a tap-out system that is extremely effective though.

  Unrelated, but I despise the tap-out rebound. All I can think of when I see it is "unskilled" or "gimmicky".

I always do it when I play but the ball either goes to the wrong team or hits someone hard on the face. ???
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