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IndyRealist
12-06-2017, 11:37 PM
Real plus-minus (RPM) was developed by Jeremias Engelmann, formerly of the Phoenix Suns, in consultation with Steve Ilardi, University of Kansas psychology professor and former NBA consultant.

It follows the development of adjusted plus-minus (APM) by several analysts and regularized adjusted plus-minus (RAPM) by Joe Sill.

RPM reflects enhancements to RAPM by Engelmann, among them the use of Bayesian priors, aging curves, score of the game and extensive out-of-sample testing to improve RPM's predictive accuracy.

This guide is going to be broken into two posts. The first will be some brief history on the statistic, and what it’s trying to accomplish. The second will be issues with RPM, and how we use it wrong. This is not meant to be exhaustive, or detail how to actually calculate RPM, but rather to give everyone a good idea on what the stat is and what it can (and can’t) do. Almost all the math will be skipped, because no one really cares about that. There will be a link at the bottom if anyone really wants it.

1. What is RPM

RPM stands for Real Plus-Minus, which is really just marketing talk. It is a derivative of xRAPM, or Expected Regularized Adjusted Plus-Minus, which was created by Engelmann. xRAPM is, as you would expect, itself a derivative of RAPM, which is a derivative of APM, which was an attempt to fix the OG plus-minus.

PM in it’s most basic form is how much the score changes when a player is on the floor. This can be looked at for individuals, combinations of multiple players, or entire lineups. The issue with PM at an individual level is noise. There are 9 other players on the floor at any given time (4 teammates and 5 opponents) all contributing varying amounts to the final score. How can you attribute that to one player? It becomes even more difficult when two or more players play so much of their minutes together that PM cannot tell them apart. This is called collinearity. The example I give is Kobe Bryant and Derek Fisher. Whenever Fisher was on the floor, Bryant almost always was as well. Essentially, PM said they were equally impactful, despite how absurd that statement is.

APM uses linear regression to model the minutes the players are apart to attempt to isolate one player from the rest. Unfortunately, this does not resolve collinearity, since the minutes Fisher and Bryant were apart were so few that you ended up with extremely small samples wildly swinging the data.

RAPM attempts to solve this problem by applying ridge regression, which pulls the data toward a prior, or predetermined expectation. RAPM uses a player’s previous seasons as the prior. If a player rates higher or lower than previous seasons would indicate, RAPM assumes that is a fluke that will average out long term, and pulls the rating closer to previous seasons. The unfortunately has the effect of throwing out a lot of relevant data.

Consider a rookie player. They haven’t played an 82 game season before, haven’t spent a lot of time in the weight room, are playing against grown men much bigger, stronger, and faster than any competition they’ve had before, and have to learn a whole new system. Rookies are usually bad. Now as a sophomore, that player is often substantially better, but RAPM tries to ignore those improvements, because it is skeptical of fluctuations that differ from the prior.

xRAPM (we’re almost there) is a more aggressive version of RAPM. RAPM uses a prior rating of 0, where xRAPM dynamically sets the rating. Essentially, given the Bryant/Fisher example, if there is a large positive effect, xRAPM tends towards crediting the player we think is better (Bryant).

So how is RPM different? “RPM reflects enhancements to RAPM by Engelmann, among them the use of Bayesian priors, aging curves, score of the game and extensive out-of-sample testing to improve RPM's predictive accuracy.” What does that mean? I don’t know, because ESPN has not published how to calculate RPM. Presumably, aging curves account for things like the rookie/sophomore example above. Bayesian priors refers to the regression. The rest is gibberish. If someone with more statistical background than me wants to take crack at it, links are below:

https://cornerthreehoops.wordpress.com/2014/04/17/explaining-espns-real-plus-minus/

https://deadspin.com/just-what-the-hell-is-real-plus-minus-espns-new-nba-s-1560361469

https://www.poundingtherock.com/2014/4/8/5594238/problem-with-real-plus-minus

The math:
https://squared2020.com/2017/09/18/deep-dive-on-regularized-adjusted-plus-minus-i-introductory-example/

IndyRealist
12-06-2017, 11:37 PM
2. What do we get wrong about RPM?

A) The first and most glaring issue with how we use RPM is that it doesn’t tell you what happened. Why? From above “If a player rates higher or lower than previous seasons would indicate, RAPM assumes that is a fluke that will average out long term, and pulls the rating closer to previous seasons.“ RPM uses prior seasons as a template for the current one, and pulls the current data toward what happened in previous years. As a result, except in the case of rookies RPM never actually shows you what happened THIS YEAR. What RPM is designed to do is predict what’s going to happen. “If my primary goal is to evaluate how well a player did this season, it wouldn’t make a lot of sense to use data from other seasons. However, if I want to predict what will happen in the future, the older numbers can help me differentiate between players who have been consistently good (and will likely keep being good) and players who are merely going through a hot streak (and will likely regress to their mean).”

Take for example Lebron James. At the time I write this, he has career highs in TS%, 2pt FG%, 3pt FG%, assist rate, and 2nd highest rebounding rate. He is 2nd in Win Shares, 2nd in BPM, 2nd in PER, and 1st in VORP. In RPM he’s 4th. This is likely because Lebron is posting numbers substantially higher than he has in the last 3 years, and because of ridge regression RPM thinks that it’s a fluke and that Lebron will regress to the mean. Thus, his RPM value is lower for this year than what EVERYTHING ELSE suggests. The crux is that RPM should not be used to say, “Lebron James is not in the running for MVP.” RPM never really says that player A has outperformed player B, it says it thinks that player A will outperform player B “IN THE FUTURE”.

B) The next issue is with how the priors are rated. Remember that RAPM uses a prior rating of 0, meaning that it’s extremely skeptical of new data. RPM uses a variable prior rating which skews the data to try and throw out less. Essentially, we KNOW that Kobe Bryant is better than Derrick Fisher, so we’re going to count Kobe for more. Every player has a different prior rating, reflecting how confident RPM is that new data is a fluke. So, how is the rating determined? Who knows. Again, ESPN has not saw fit to publish their calculations, and there is no consensus in economics on how it should be done. For all we know, there’s a keyboard monkey in Bristol who just types in numbers manually based on what he thinks. More likely, there’s some complex calculation that pulls in non-PM boxscore data. Regardless, what we know is that RPM DOES NOT TREAT ALL DATA EQUALLY. By design, RPM biases the data.

C) Position matters. The average value for centers is different than the average for point guards. RPM is not position adjusted like PER, where an average player at any position is 15.00. Comparing across positions is tenuous.

D) It doesn’t necessarily work. This is a problem inherent in all PM based statistics, and what every single iteration has tried to correct. Does RPM really differentiate between a player and his teammates? A good example is 2014 Jae Crowder, who ranked 9th among SFs that year. I’m just going to quote this, because I can’t say it any better.


Jae Crowder is used primarily in a specific role in a certain line-up -- he's the small forward when Carlisle makes his second rotation of the half. Carlisle takes Dirk out early and goes with a small-ball team with Shawn Marion at the four, then he brings Dirk back in with Crowder, Brandan Wright and Devin Harris. That unit absolutely kills opposing second teams and Jae has very little to do with it.

All the Mavs are asking him to do is pass the ball, don't turn it over and be passable at defense. They run pick-and-rolls with Dirk or Wright and Jae is one of the guys who rotates the ball off the pick-and-roll. He's a league-average shooter who doesn't take many shots. The ones he takes generally tend to be open and he scores 10 points on 44% shooting per-36 minutes. There's just not much going on with the guy.

Jae is literally out there to give Shawn Marion a breather. Marion plays 31 minutes, splitting those between the three and four. The minutes Marion doesn't play at the three, Carlisle splits between Crowder and Vince Carter. Crowder will get spot minutes in a blow-out or when Marion can't go, but playing at the three when Dirk and Wright are in the game is the only defined role he has on this team.

Anything that measures the output of the possessions that Jae Crowder is on the floor is only measuring how well the Mavericks are doing as a team in that one role. He spots up and shoots threes at a league average rate and he is a decent defender at the wing position. The Mavs can't give the line-up he is in more minutes because a team that played Wright and Dirk together for more than 15+ minutes would not have enough rebounding or interior defense.

The only reason Dallas can get away with using that line-up -- the one that makes Crowder an effective player -- is because Carlisle uses it for four to five minute stretches against second units. He's putting Dirk and Wright, two of the most efficient offensive players in the NBA, against what are usually straight up terrible defenders. Backup fours and fives have pretty much zero chance of guarding Dirk or Wright. Just as important, they can't exploit their "defense" at those positions.
https://www.mavsmoneyball.com/2014/4/9/5591108/jae-crowder-problem-espn-real-plus-minus-rpm

FlashBolt
12-06-2017, 11:39 PM
Props for your effort. Will read tomorrow. I think there should be a basketball guide involving statistics. Sticky it and have it explained so a ten year old could understand. Who's up to contribute?

FlashBolt
12-07-2017, 12:04 AM
It's no secret that analytics have been vital in NBA's progression over these past few years. This is going to be a thread that I would hope could spread some knowledge regarding some advanced statistics being used. This isn't going to be a debate but purely a knowledge-based thread where we can all contribute. Please do not use this thread and turn it into a LeBron vs Curry or Jordan vs LeBron thread UNLESS you are using it as context to explain the advanced statistic. At the moment, I am still finding posters who are interested. However, if you are interested, just post below and I'll organize the list.

Requirements:
1) Try to explain it in a way that a casual fan would understand. Many of us began as casual fans and aren't basketball scouts. We don't need a Harvard-translated definition.

2) Use examples if it helps but do NOT turn this into a debate thread.

3) Feel free to correct or add to a definition respectfully. Some of us know more than another. That's perfectly fine. We all have something worthy to contribute at the end of the day.

4) You can use Basketball-Reference but I think we would all prefer some originality in your example.

Some advanced statistics you could work on:
PER, VORP, BPM, RPM, TS%, EFG%, USG%, WS48, WS TOTAL.

aman_13
12-07-2017, 12:16 AM
Thanks Indy!

Can the mods please sticky this?

We can use this thread as a reference.

FlashBolt
12-07-2017, 12:17 AM
PER: Measures the productivity of a player in a per-minute basis, it takes into account the positive and negative contributions of a player. This stat does not favor defensive contributions and heavily favors offensive contributions. This stat also takes into account for pace. However, it is not ranking of how good a player is. We've seen examples where players with very few minutes played experience a high PER measurement (Hassan Whiteside 2014-2015), and we've seen players such as Draymond Green (PER of 16.5 in 2016-2017) experience slightly above average PER. For reference, the average PER for the league has been measured to be 15.

TS%:

EFG%:

FtR%:


WS Total:

WS48:

VORP:

BPM:

RPM:

FlashBolt
12-07-2017, 12:22 AM
Thanks Indy!

Can the mods please sticky this?

We can use this thread as a reference.

I'm making an official thread where we can all add and contribute to an overall glossary of advanced statistics. I'll add this to it if Indy Realist permits.

Vee-Rex
12-07-2017, 02:11 AM
I was spat on, pissed on, crucified for saying the exact same thing about PM stats. I clearly defined how there were so many variables (coaching schemes, rotations, player roles) that were completely unrelated to the player that would make PM stats unreliable as a sole measurement.

Use it IN CONJUNCTION with a multitude of other stats - not by itself or you'll be fooled into thinking the George Hills, Kyle Lowrys, and Dellevadovas are better than Kyrie. Funny how Kyrie's advanced stats did a massive 180 when switching to a different team with different schemes, players, coaching, and culture!

Extreme but accurate example: I would have higher PM stats if I played on a team with 4th graders compared to Kemba Walker playing on an Olympic team. Does that mean I'm a better/superior player than Kemba? No.

I like RPM but it is used SOOO incorrectly and it should NEVER be used as the SOLE and ONLY stat to declare one player as being superior or more impactful or more conducive to winning than another.

/mic drop

FlashBolt
12-07-2017, 02:18 AM
I was spat on, pissed on, crucified for saying the exact same thing about PM stats. I clearly defined how there were so many variables (coaching schemes, rotations, player roles) that were completely unrelated to the player that would make PM stats unreliable as a sole measurement.

Use it IN CONJUNCTION with a multitude of other stats - not by itself or you'll be fooled into thinking the George Hills, Kyle Lowrys, and Dellevadovas are better than Kyrie. Funny how Kyrie's advanced stats did a massive 180 when switching to a different team with different schemes, players, coaching, and culture!

Extreme but accurate example: I would have higher PM stats if I played on a team with 4th graders compared to Kemba Walker playing on an Olympic team. Does that mean I'm a better/superior player than Kemba? No.

I like RPM but it is used SOOO incorrectly and it should NEVER be used as the SOLE and ONLY stat to declare one player as being superior or more impactful or more conducive to winning than another.

/mic drop

All advanced stats are similar in that way. Never understood why someone would type:

Player X is better because he has a better PER or VORP than player Y. Therefore, I have a bigger penis.

I've actually given up on using advanced statistics. I've literally enjoyed the game more just watching them play and seeing how they can actually contribute to a championship team. At the end of the day, it's about who can contribute to winning the most and some of these players generate nice numbers and stats but end up being losers. I've watched enough LeBron to admit that it's not even worth looking into advanced statistics the majority of the time. Just watch them play! I just watched RWB put up a historic individual season and after he got that triple double, it was empty as hell. No one really cared anymore. Even today, who cares? It's the past. We're losing and that's the biggest part of the game. Blake put up nice stats for years. He's, excuse my harshness, a total loser of a player. Draymond defies all advanced stats but makes winning plays. Give me that guy.

IndyRealist
12-07-2017, 08:51 AM
I'm making an official thread where we can all add and contribute to an overall glossary of advanced statistics. I'll add this to it if Indy Realist permits.

Go for it!

ewing
12-07-2017, 09:36 AM
2. What do we get wrong about RPM?

A) The first and most glaring issue with how we use RPM is that it doesn’t tell you what happened. Why? From above “If a player rates higher or lower than previous seasons would indicate, RAPM assumes that is a fluke that will average out long term, and pulls the rating closer to previous seasons.“ RPM uses prior seasons as a template for the current one, and pulls the current data toward what happened in previous years. As a result, except in the case of rookies RPM never actually shows you what happened THIS YEAR. What RPM is designed to do is predict what’s going to happen. “If my primary goal is to evaluate how well a player did this season, it wouldn’t make a lot of sense to use data from other seasons. However, if I want to predict what will happen in the future, the older numbers can help me differentiate between players who have been consistently good (and will likely keep being good) and players who are merely going through a hot streak (and will likely regress to their mean).”

Take for example Lebron James. At the time I write this, he has career highs in TS%, 2pt FG%, 3pt FG%, assist rate, and 2nd highest rebounding rate. He is 2nd in Win Shares, 2nd in BPM, 2nd in PER, and 1st in VORP. In RPM he’s 4th. This is likely because Lebron is posting numbers substantially higher than he has in the last 3 years, and because of ridge regression RPM thinks that it’s a fluke and that Lebron will regress to the mean. Thus, his RPM value is lower for this year than what EVERYTHING ELSE suggests. The crux is that RPM should not be used to say, “Lebron James is not in the running for MVP.” RPM never really says that player A has outperformed player B, it says it thinks that player A will outperform player B “IN THE FUTURE”.

B) The next issue is with how the priors are rated. Remember that RAPM uses a prior rating of 0, meaning that it’s extremely skeptical of new data. RPM uses a variable prior rating which skews the data to try and throw out less. Essentially, we KNOW that Kobe Bryant is better than Derrick Fisher, so we’re going to count Kobe for more. Every player has a different prior rating, reflecting how confident RPM is that new data is a fluke. So, how is the rating determined? Who knows. Again, ESPN has not saw fit to publish their calculations, and there is no consensus in economics on how it should be done. For all we know, there’s a keyboard monkey in Bristol who just types in numbers manually based on what he thinks. More likely, there’s some complex calculation that pulls in non-PM boxscore data. Regardless, what we know is that RPM DOES NOT TREAT ALL DATA EQUALLY. By design, RPM biases the data.

C) Position matters. The average value for centers is different than the average for point guards. RPM is not position adjusted like PER, where an average player at any position is 15.00. Comparing across positions is tenuous.

D) It doesn’t necessarily work. This is a problem inherent in all PM based statistics, and what every single iteration has tried to correct. Does RPM really differentiate between a player and his teammates? A good example is 2014 Jae Crowder, who ranked 9th among SFs that year. I’m just going to quote this, because I can’t say it any better.


Thanks Indy. that was a good read

KnicksorBust
12-07-2017, 12:19 PM
In basketball, true shooting percentage is an APBRmetrics statistic that measures a player's efficiency at shooting the ball. It is intended to more accurately calculate a player's shooting than field goal percentage, free throw percentage, and three-point field goal percentage taken individually.

TS% should always be used instead of FG%. Simple reason why:

Dwight Howard shoots 6 for 10 from the field.
Steph Curry shoots 4 for 10 from the field.

If you just compare FG% it would appear that Dwight Howard is the more efficient offensive players. However, let's add more context.

Dwight Howard shoots 6 for 10 from the field. These shots are all 2pt attempts. He also makes 4 out of 8 from the free throw line. Dwight Howard has scored 16 points.

Steph Curry shoots 4 for 10 from the field. These shots are all 3pt attempts. He also makes 7 out of 8 from the free throw line. Steph Curry has scored 19 points.

They have both shot exactly the same amount of field goal attempts and free throw attempts. Steph Curry's TS% would be higher because it would give him added value for shooting 3's and shooting a higher percentage from the free throw line. Those are the two important aspects of basketball that true shooting percentage successfully incorporates that field goal percentage does not.

Scoots
12-07-2017, 12:22 PM
Good reading Indy. I think people always look for a single number that is "the answer".

Scoots
12-07-2017, 12:57 PM
TS% should always be used instead of FG%.

No. TS% is just another data point, it's not a replacement for FG%. TS% has issues too in that it undervalues great FT% and overvalues bad FT%. It's not useless but it's not a replacement for basic data either.

PPP is probably a more useful stat than TS% for figuring out a players offensive efficiency, but like all stats PPP has it's own set of caveats.

lol, please
12-07-2017, 02:22 PM
So this is a place to copy paste advanced stat definitions from basketball-reference? [emoji846]

Sent from my Note 8 using Tapatalk

aman_13
12-07-2017, 02:32 PM
I'm making an official thread where we can all add and contribute to an overall glossary of advanced statistics. I'll add this to it if Indy Realist permits.

Can you add Indy's post? Or anyone? If not, I'll do it when I get a chance.

IndyRealist
12-07-2017, 02:38 PM
No. TS% is just another data point, it's not a replacement for FG%. TS% has issues too in that it undervalues great FT% and overvalues bad FT%. It's not useless but it's not a replacement for basic data either.

PPP is probably a more useful stat than TS% for figuring out a players offensive efficiency, but like all stats PPP has it's own set of caveats.

FG% should never be used in this day and age. I always quote 2pt FG and 3pt FG seperately. eFG% is the most direct replacement for FG%.

FlashBolt
12-07-2017, 06:15 PM
FG% should never be used in this day and age. I always quote 2pt FG and 3pt FG seperately. eFG% is the most direct replacement for FG%.

Do you mind adjusting your beginning post and make it a general advanced statistics thread? That way we won't have to scroll through pages to find it.

WaDe03
12-07-2017, 07:11 PM
IDGAF - a measure that determines the amount of ****s given is 0.

aman_13
12-07-2017, 07:50 PM
FG% should never be used in this day and age. I always quote 2pt FG and 3pt FG seperately. eFG% is the most direct replacement for FG%.

eFG% shouldn't even be considered an advanced stat anymore. In fact, Basketball Reference has it categorized in their per game stats.

KnicksorBust
12-07-2017, 08:51 PM
TS% should always be used instead of FG%.

No. TS% is just another data point, it's not a replacement for FG%. TS% has issues too in that it undervalues great FT% and overvalues bad FT%.

Based on what?

ChiSox219
12-07-2017, 10:51 PM
Based on what?

i'm also wondering the same

HandsOnTheWheel
12-08-2017, 03:23 AM
IDGAF - a measure that determines the amount of ****s given is 0.

:laugh2:

Scoots
12-08-2017, 08:35 AM
FG% should never be used in this day and age. I always quote 2pt FG and 3pt FG seperately. eFG% is the most direct replacement for FG%.

I'm unwilling to say that any stat should never be used. All stats have a context and if everybody in the discussion doesn't understand any of the stats being used it all falls apart. I too use 2FG%, 3FG%, and eFG%.

Scoots
12-08-2017, 08:52 AM
Based on what?

Based on TS% using a constant of .44 as the value of a free throw attempt. It's an estimated value applied to all players equally for FTs attempted on regular fouls and and 1 attempts. By playing with hypothetical numbers you can get some strange results. It's fine, it's just not the be all and end all of shooting stats. Daryl Morey supposedly created TS% and even he said it's got issues.

ChiSox219
12-08-2017, 11:29 AM
Based on TS% using a constant of .44 as the value of a free throw attempt. It's an estimated value applied to all players equally for FTs attempted on regular fouls and and 1 attempts. By playing with hypothetical numbers you can get some strange results. It's fine, it's just not the be all and end all of shooting stats. Daryl Morey supposedly created TS% and even he said it's got issues.

But poor free throw shooters like Shaq and Deandre have multiple seasons with lower TS% than eFG% because of their low ft%.

IndyRealist
12-08-2017, 11:51 AM
I'm unwilling to say that any stat should never be used. All stats have a context and if everybody in the discussion doesn't understand any of the stats being used it all falls apart. I too use 2FG%, 3FG%, and eFG%.

FG% has not said anything useful since the 3pt line was implemented. It literally obfuscates the data.

Vee-Rex
12-08-2017, 03:44 PM
Based on TS% using a constant of .44 as the value of a free throw attempt. It's an estimated value applied to all players equally for FTs attempted on regular fouls and and 1 attempts. By playing with hypothetical numbers you can get some strange results. It's fine, it's just not the be all and end all of shooting stats. Daryl Morey supposedly created TS% and even he said it's got issues.

TS% also doesn't differentiate between made or missed baskets, which tends to have an impact on the game. For example:

Player A: 3/5 from 2-point range for 6 points
Player B: 2/5 from 3-point range for 6 points

Both players have the same TS% - their output being 6 points in 5 possessions. However, Player B has 1 more missed field goal. That means 1 more opportunity the opposing team has at initiating a fast break (especially if it's a long rebound from the 3-point shot). That means less momentum which tends to affect morale for both teams.

Sometimes efficiency can be a little overrated in the sense that it doesn't necessarily impact the game as much as we might believe. One of the reasons why Jordan's scoring was so freaking incredible was not because he was the most efficient player (his best single season tops at .614TS%), but because HE MADE BASKETS. He just put the doubt of stopping him into his opponents minds.

Sometimes making more baskets (vs. just making 3's and living at the free throw line for high TS%) has a bit more of a dominant impact. That's why I don't look ONLY at TS% even if it's the best single stat we have to measure efficiency.

FlashBolt
12-08-2017, 03:52 PM
TS% also doesn't differentiate between made or missed baskets, which tends to have an impact on the game. For example:

Player A: 3/5 from 2-point range for 6 points
Player B: 2/5 from 3-point range for 6 points

Both players have the same TS% - their output being 6 points in 5 possessions. However, Player B has 1 more missed field goal. That means 1 more opportunity the opposing team has at initiating a fast break (especially if it's a long rebound from the 3-point shot). That means less momentum which tends to affect morale for both teams.

Sometimes efficiency can be a little overrated in the sense that it doesn't necessarily impact the game as much as we might believe. One of the reasons why Jordan's scoring was so freaking incredible was not because he was the most efficient player (his best single season tops at .614TS%), but because HE MADE BASKETS. He just put the doubt of stopping him into his opponents minds.

Sometimes making more baskets (vs. just making 3's and living at the free throw line for high TS%) has a bit more of a dominant impact. That's why I don't look ONLY at TS% even if it's the best single stat we have to measure efficiency.

Great point. It also ignores the overall scoring ability of a player in causing threats elsewhere offensively. I hope we can move away from stats just for a bit these days. It's getting a tad-bit repetitive and takes away from actually enjoying the game.

Scoots
12-08-2017, 04:37 PM
FG% has not said anything useful since the 3pt line was implemented. It literally obfuscates the data.

Well, it tells you how many times the ball goes through the hoop out of 100 shots during regular play by that player.

FlashBolt
12-08-2017, 06:01 PM
Well, it tells you how many times the ball goes through the hoop out of 100 shots during regular play by that player.

Doesn't really show the legitimate efficient output of a player in today's game, though. It's still being used but I'd agree that eFG% is a better measure. It's just that it also penalizes players from back then for comparison purposes as the 3P% was rarely used but as we've seen, it's probably the best weapon in the game.

Scoots
12-08-2017, 10:51 PM
Doesn't really show the legitimate efficient output of a player in today's game, though. It's still being used but I'd agree that eFG% is a better measure. It's just that it also penalizes players from back then for comparison purposes as the 3P% was rarely used but as we've seen, it's probably the best weapon in the game.

I wasn't arguing FG% was superior just that it's not useless. It, like most stats, is limited.

KnicksorBust
12-09-2017, 12:24 AM
Based on what?

Based on TS% using a constant of .44 as the value of a free throw attempt. It's an estimated value applied to all players equally for FTs attempted on regular fouls and and 1 attempts. By playing with hypothetical numbers you can get some strange results. It's fine, it's just not the be all and end all of shooting stats. Daryl Morey supposedly created TS% and even he said it's got issues.

You are still being vague. Why is .44 wrong? What strange results?

Scoots
12-11-2017, 07:31 PM
You are still being vague. Why is .44 wrong? What strange results?

The .44 is an average of regular free throws on fouls, 3 free throws, flagrants, technicals, and and-1s. Some players are better than average and some are worse and it slants the results. It's a fine stat, it's just not perfect ... but there is no perfect.

KnicksorBust
12-12-2017, 12:31 PM
The .44 is an average of regular free throws on fouls, 3 free throws, flagrants, technicals, and and-1s. Some players are better than average and some are worse and it slants the results. It's a fine stat, it's just not perfect ... but there is no perfect.

So... better than average free throw shooters improve their true shooting percentage and below average free throw shooters don't. Again that sounds like a good thing. If you don't have an actual valid response you can just say "I don't like it" and we can move on but you aren't showing any reason why .44 is wrong or citing specific examples. I think TS% is the best offensive scoring efficiency stat. Not trolling here I legitimately thought you had something to add to the discussion.

Scoots
12-12-2017, 03:53 PM
So... better than average free throw shooters improve their true shooting percentage and below average free throw shooters don't. Again that sounds like a good thing. If you don't have an actual valid response you can just say "I don't like it" and we can move on but you aren't showing any reason why .44 is wrong or citing specific examples. I think TS% is the best offensive scoring efficiency stat. Not trolling here I legitimately thought you had something to add to the discussion.

Jeez ... glad you are not trolling :)

TS% bugs me because a part of it is an estimate. We have the details available to not use .44 but use the actual number of and-1s and technicals and flagrants each player attempts. Why not use the real numbers when we have them?

Chronz
12-12-2017, 04:07 PM
Scoots doesn't know ts%, it was around long before Morey and we can easily account for actual possessions. .44 was an estimate but it remains a reliable one even when looking at the actual ranks

Chronz
12-12-2017, 04:09 PM
Jeez ... glad you are not trolling :)

TS% bugs me because a part of it is an estimate. We have the details available to not use .44 but use the actual number of and-1s and technicals and flagrants each player attempts. Why not use the real numbers when we have them?

Because its negligible for the most part and it's still better than ignoring the value of free throws altogether

Scoots
12-12-2017, 06:13 PM
Scoots doesn't know ts%, it was around long before Morey and we can easily account for actual possessions. .44 was an estimate but it remains a reliable one even when looking at the actual ranks

https://en.wikipedia.org/wiki/Daryl_Morey

I heard him talk about it (via audio only) from a Sloan conference. So either he's lying or you are wrong.

Scoots
12-12-2017, 06:13 PM
Because its negligible for the most part and it's still better than ignoring the value of free throws altogether

That's true ... but why not get it right?

valade16
12-12-2017, 07:23 PM
That's true ... but why not get it right?

I'd imagine because it would take far more manpower and time to calculate the TS% based on the individual player's specific stats. That would be my guess at least.

Scoots
12-13-2017, 01:07 AM
I'd imagine because it would take far more manpower and time to calculate the TS% based on the individual player's specific stats. That would be my guess at least.

When TS% was created all the other numbers were not readily available, but they are now. And computers don't use manpower :)

IndyRealist
12-13-2017, 08:27 AM
When TS% was created all the other numbers were not readily available, but they are now. And computers don't use manpower :)

It does take manpower initially. Someone has to code it. And there doesn't seem to be much enthusiasm to correct it. If I had to guess, that's because A) it's accurate enough for everyone but extreme outliers, and B) everyone with access to the databases are already vested in other proprietary metrics.

Scoots
12-13-2017, 10:10 AM
It does take manpower initially. Someone has to code it. And there doesn't seem to be much enthusiasm to correct it. If I had to guess, that's because A) it's accurate enough for everyone but extreme outliers, and B) everyone with access to the databases are already vested in other proprietary metrics.

I agree, heck ESPN considers anything but the original 5 counting stats as "advanced" :)

FlashBolt
12-13-2017, 02:27 PM
I agree, heck ESPN considers anything but the original 5 counting stats as "advanced" :)

ESPN is for casuals, though. But I've been hearing more and more commentators/analysts bring up advanced stats now. I guess they are seeing the trend and try to sound more informed but I can bet some of them have no idea what it is other than what they are being told to say.

lol, please
12-18-2017, 01:59 PM
Scoots doesn't know ts%, it was around long before Morey and we can easily account for actual possessions. .44 was an estimate but it remains a reliable one even when looking at the actual ranksClearly.

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lol, please
12-18-2017, 02:01 PM
FG% should never be used in this day and age. I always quote 2pt FG and 3pt FG seperately. eFG% is the most direct replacement for FG%.Well said.

I see eFG% used more often / brought up in discussions these days and it's a good thing.

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Scoots
12-18-2017, 04:19 PM
Clearly.

So you are saying Morey is a liar?

IndyRealist
12-18-2017, 09:23 PM
Maybe things are turning around. Effective field goal percentage was mentioned 7 times in this week's power rankings on NBA.com.

http://www.nba.com/powerrankings/#/

Chronz
12-19-2017, 09:56 AM
So you are saying Morey is a liar?

He never said it bro. It's been around since the late 80s to my knowledge, possibly the late 70s and at the very least early 2000s when Morey was still interning in Boston

Scoots
12-19-2017, 01:06 PM
He never said it bro. It's been around since the late 80s to my knowledge, possibly the late 70s and at the very least early 2000s when Morey was still interning in Boston

I don't have access to the original audio anymore. But you can google it and find that Morey is widely credited with creating what we now call TS% with that specific formula. Maybe what you are remembering is something different, or maybe Morey has been taking credit and being given credit for something he stole ... but it does seem unlikely.

FlashBolt
12-22-2017, 03:42 AM
Maybe things are turning around. Effective field goal percentage was mentioned 7 times in this week's power rankings on NBA.com.

http://www.nba.com/powerrankings/#/

They've been pushing it on their site as well. NBA.com is probably the best source for checking and comparing stats. ESPN has pushed the advanced metrics deep as well. It's a bit odd as they are geared towards casuals but with the internet/social media booming, it only makes sense that they push it.