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Neil Paine
Joined: 13 Oct 2005
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 Posted: Tue May 25, 2010 4:32 pm Post subject: |
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I guess the key question for schtevie is, what level of APM skill would you be unwilling to pay more than the league-minimum salary for? The answer is your replacement level.
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schtevie
Joined: 18 Apr 2005
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| Posted: Wed May 26, 2010 10:44 am Post subject: |
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What a muddle.
| HoopStudies wrote: | | schtevie wrote: |
"Replacement player value" is not and cannot be a synonym for "relevant opportunity cost", except by mere coincidence.
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Would you like to explain this or are you stating it's true by decree? |
I am stating that this is true according to commonly accepted definitions. What is the definition of opportunity cost? It is the next-best choice available/foregone. Not the worst. What are replacement level players? They are by definition the worst players in the league.
Accordingly, unless one believes that wild and unrealistic managerial behavior describes the norm (say, should the owner of the Cavs, were he not able to resign LBJ would instead replace him with some random SF from the D-league) replacement level is clearly only relevant when such players are the next-best option, that is when you are replacing replacement level players or in some instances those slightly above.
(And yes, I can imagine an exception that proves the rule. Say there were multiple injuries to a starter and his primary sub, then scraping the bottom of the barrel becomes relevant. But the point stands.)
| HoopStudies wrote: | | schtevie wrote: |
First of all, Dean, I don't know why you are mixing on-court productivity with financial compensation here. Things, apparently, are confused enough already. And breakfast cereal analogies are not illuminating.
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As Neil says, if you don't understand this, then you aren't going to understand any of the arguments here. Cost and benefit. There is a minimal cost for any player. If all you are interested in is rating players, then replacement level is of lesser interest. But if you have to make decisions involving money, it matters. |
Dean, in a lawyerly sense, how can I or anyone disagree with this last sentence? Does money matter? Yes. Do replacement players cost money? Yes. Therefore replacement players matter. Yes. But there is little nutritional value therein for the debate at hand.
If an NBA franchise is going to field a team, it needs practice bodies, it needs insurance against injury to the best players, and it needs players to keep the players above them honest, and sometimes to humor the coaching staffs in their belief - true or not - that they can identify match-up advantages. All these functions call for replacement level players (and those slightly above. What is the agreed-upon definition for replacement players again?) If you need these functions fulfilled, you need warm bodies that cost money, and, on average, each NBA team grabs five out of the bottom 150 players who suit up.
These functions however are essentially independent of the valuation of the better talent and the expenditure of resources on them.
It is in this sense that explicitly introducing the concept of budget constraint (with all the byzantine, CBA bells and whistles and variation depending on franchise location and competitive standing) to the discussion is counterproductive.
| HoopStudies wrote: | | schtevie wrote: |
My point is that there is no relevant, informative replacement value.
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I would agree that there is no unique replacement value. But no relevant? |
See above.
| HoopStudies wrote: | | schtevie wrote: |
If one is considering replacing Zydrunas Ilgauskas, say, with Shaquille O'Neal. The analysis ultimately centers on how many net points one produces in comparison to the other, and the manner in which they are assumed to do so.
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Not completely true. If you know guys get injured, how much they don't play and get replaced by some replacement level guy, then you need that replacement level to really understand the deal. |
That I did not explicitly mention contingencies of injury (or, say, the impact of aging with a multi-year contracts) was of course only due to a desire to emphasize the essential, core point. But this aside, the replacement level still isn't required to "really understand the deal". Replacement level players are going to be on a team as a class, independent of the existence of starters, independent of players 6 through 10 (but wait, is the 10th player a replacement, or not? I cannot remember.)
One may decide if one has an injury-prone starter whose functions are a core part of the defense or offense, to invest a bit more in his insurance. (But are we then talking about a non-replacement player?) But the general decision to insure is not part of the rational calculation. That cost is sunk.
| HoopStudies wrote: | | schtevie wrote: |
If however one is looking for a new bench warmer to replace a bench warmer, fine, by all means compare him to a referential bench warmer. But at least compare to the relevant position and not some non-existent composite.
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This is purely semantics. Replacement level is non-unique, so yes, you can do one for varying positions (or a number of reasons). But people here have generally looked for a league standard and that's fine. Certainly far better than arguing there is no relevant or informative value. |
Dean, it is not a semantic distinction at all. Sure, it is educational to know what the general distribution of player value is throughout the league. And perhaps a consensus could gather around some particular percentile (or range) representing the average contributions of a notional "replacement level" player.
But such a concept, as a concept itself, would have little if any operational value. It is the details that matter.
| HoopStudies wrote: |
| schtevie wrote: |
| mtamada wrote: | ...
People who ignore replacement level will overvalue the longer minutes but lower performing player. We see this all the time in Hall of Fame debates, where all too often the arguments are made based on the accumulation of stats such as points and rebounds, and even per game statistics, and too little attention is paid to the player's performance level. (The problem is even worse in baseball where some people will point at Pete Rose's 4,256 hits, and fail to take into account how many outs he made in accumulating those hits.) |
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It is simply not the case that ignoring replacement level (whatever that is - and again, the problem in basketball is estimating value, which obtains to determining any notional benchmark. Assuming an accurate and precise benchmark - even if of dubious comparative value - isn't a solution.) overvalues or undervalues any type of player. Any such analysis must be coherent and stand on its own.
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Huh? MikeT is completely on target here. |
I will let Mike argue the point if he wishes, but a particular word about the BHOF voting in particular. Though I don't hold these electors in particularly high regard, generally, in this instance I find it difficult to find fault with their decision making - if the criterion is basketball fame. Part of what goes into "fame" is longevity, and this necessarily means that players deteriorate toward replacement value (whatever that is). This is not a problem nor a point of confusion on their part; it is one of the criteria. The HOF is not (necessarily) a Hall of Merit, and the misperceptions of value are the scandal.
| HoopStudies wrote: |
| schtevie wrote: |
And just to emphasize the point, the motivation of this detour was the discussion of VORP in terms of the draft. Such an exercise perfectly illustrates the shortcomings. Every player in the draft, from the highly skilled lottery picks to the workhorses of the late second round are compared against a common imprecise composite. Again, to what gain?
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Draft picks, in particular, need to be evaluated against a replacement level because many are not that different from the easy-to-obtain free agent at replacement level. |
I am sure I am belaboring the point, but the draft is a different application, so on I go. I am not going to argue that, on average, late first round or second round picks don't end up that much different than replacement players. (DSMok1's lovely graphs clearly show this - again contingent upon agreement about what a replacement level player is. And as such, my preference would be to not muck up a graph presenting this information by subtracting each of these contributions from a notional replacement value. Let this information be somewhere in the title if at all.) However, the draft is different from other player transactions in that each pick has significant option value. You don't see teams trading draft rights for replacement players, which nicely summarizes my point.
On to baseball...
| HoopStudies wrote: |
| schtevie wrote: |
Finally,
| gabefarkas wrote: | schtevie wrote:
This isn't baseball, where because of the rules of the game, the worst players basically get as many at bats as the best.
Umm, just as an aside, that's not actually true. Batting order dictates that some players will consistently get more plate appearances than others. Worse hitters are at the back of the lineup, just like worse shooters in basketball tend to take less FGA. |
Let me restate: basically, the worst players get as many at bats as the best. |
Again, huh? For guys on a roster all season long, you can see guys with 700 plate appearances and guys with 100. And, as Gabe says, guys at the top of a lineup inherently can get 100+ extra plate appearances a season over guys at the bottom. Don't get ridiculous. |
If one makes the most reasonable, contextual interpretation of my remark made in brief, it is not really vexing. The observation was rule-based: a player at the bottom of the order will necessarily bat up to one time less per game than the player at the top of the order (unless removed for another replacement player or specialist). As such, bottom of the order guys/replacement players are far more important in baseball than in basketball. |
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Neil Paine
Joined: 13 Oct 2005
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| Posted: Wed May 26, 2010 11:07 am Post subject: |
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Schtevie, it sounds like your problem with replacement level analysis would be assuaged by what's called "chaining":
viewtopic.php?t=1086
In that variation, an injured LBJ would be replaced by a backup-caliber SF, and that backup-caliber SF would be replaced by an NBDL SF.
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Last edited by Neil Paine on Wed May 26, 2010 11:27 am; edited 2 times in total |
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DSMok1
Joined: 05 Aug 2009
Posts: 611
Location: Where the wind comes sweeping down the plains
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| Posted: Wed May 26, 2010 11:07 am Post subject: |
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| schtevie wrote: |
I am stating that this is true according to commonly accepted definitions. What is the definition of opportunity cost? It is the next-best choice available/foregone. Not the worst. What are replacement level players? They are by definition the worst players in the league.
Accordingly, unless one believes that wild and unrealistic managerial behavior describes the norm (say, should the owner of the Cavs, were he not able to resign LBJ would instead replace him with some random SF from the D-league) replacement level is clearly only relevant when such players are the next-best option, that is when you are replacing replacement level players or in some instances those slightly above.
(And yes, I can imagine an exception that proves the rule. Say there were multiple injuries to a starter and his primary sub, then scraping the bottom of the barrel becomes relevant. But the point stands.) |
If, during the season, LBJ is hurt and lost for the season, who takes his place on the roster? That is his replacement. The margin between LBJ and whoever took his place on the roster is the value of LBJ. Thus VORP.
That said, because of the potential for secondary players to up their minutes played, the calculation isn't so simple. Also, roles are limited.
A quick case study of the Orlando Magic:
| Code: | Player MP WS WS/48
Dwight Howard 2843 13.2 0.223
Rashard Lewis 2369 6.5 0.132
Vince Carter 2310 7.4 0.154
Matt Barnes 2097 5.9 0.135
Jameer Nelson 1860 5 0.13
J.J. Redick 1808 6.5 0.173
Jason Williams 1703 4.5 0.127
Mickael Pietrus 1687 3.6 0.103
Marcin Gortat 1088 3.4 0.151
Ryan Anderson 910 3.1 0.161
Brandon Bass 648 2 0.147
Anthony Johnson 406 1 0.116
Wins: 62.1
Same Minute Distribution, W/O Dwight Howard:
Player MP WS WS/48
Rashard Lewis 2843 7.8 0.132
Vince Carter 2369 7.6 0.154
Matt Barnes 2310 6.5 0.135
Jameer Nelson 2097 5.7 0.13
J.J. Redick 1860 6.7 0.173
Jason Williams 1808 4.8 0.127
Mickael Pietrus 1703 3.7 0.103
Marcin Gortat 1687 5.3 0.151
Ryan Anderson 1088 3.6 0.161
Brandon Bass 910 2.8 0.147
Anthony Johnson 648 1.6 0.116
Any Old Joe 406 0.2 0.025
Wins: 56.3
Same Minute Distribution, W/O Rashard Lewis:
Player MP WS WS/48
Dwight Howard 2843 13.2 0.223
Vince Carter 2369 7.6 0.154
Matt Barnes 2310 6.5 0.135
Jameer Nelson 2097 5.7 0.13
J.J. Redick 1860 6.7 0.173
Jason Williams 1808 4.8 0.127
Mickael Pietrus 1703 3.7 0.103
Marcin Gortat 1687 5.3 0.151
Ryan Anderson 1088 3.6 0.161
Brandon Bass 910 2.8 0.147
Anthony Johnson 648 1.6 0.116
Any Old Joe 406 0.2 0.025
Wins: 61.6 |
Hmmm. Maybe this is more tricky than I thought... |
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DSMok1
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Neil Paine
Joined: 13 Oct 2005
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Guy
Joined: 02 May 2007
Posts: 128
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| Posted: Wed May 26, 2010 11:37 am Post subject: |
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| Just speaking to the baseball analogy, the difference just isn't that big. Yes, basketball teams can give good offensive players more scoring opportunities within a game in a way baseball teams can't. But that's much less true for defense. And starters in baseball routinely play all 9 innings, while the best NBA players can only play about 75% of the minutes. The top 3 players in MP per team provided about 40% of all minutes this season. The top 6 hitters per baseball team (also representing about 25% of the roster) provide about 55% of the PAs. So you could actually argue that baseball gets MORE time from its best players (obviously, garbage time complicates that a bit). Bottom line, both sports give plenty of playing time to both average and below-average performers. Replacement-level is a useful concept for both sports, or neither. |
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DSMok1
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| Posted: Wed May 26, 2010 12:01 pm Post subject: |
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I'm thinking that while the scale may be off (Dwight doesn't add 12 wins actually), the order would be the same.
Say Dwight is replaced by Gortat, who is replaced by somebody near replacement level. Actual wins lost is like 6. If Gortat is hurt, somebody replaces him from near replacement level. Wins lost like 2.
So perhaps my WSoRP needs to be scaled with a factor.
Or perhaps the rate of wins is more critical than the actual playing time in evaluating the actual worth of the player. |
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gabefarkas
Joined: 31 Dec 2004
Posts: 1313
Location: Durham, NC
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| Posted: Thu May 27, 2010 3:38 pm Post subject: |
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| Guy wrote: | | Just speaking to the baseball analogy, the difference just isn't that big. Yes, basketball teams can give good offensive players more scoring opportunities within a game in a way baseball teams can't. But that's much less true for defense. And starters in baseball routinely play all 9 innings, while the best NBA players can only play about 75% of the minutes. The top 3 players in MP per team provided about 40% of all minutes this season. The top 6 hitters per baseball team (also representing about 25% of the roster) provide about 55% of the PAs. So you could actually argue that baseball gets MORE time from its best players (obviously, garbage time complicates that a bit). Bottom line, both sports give plenty of playing time to both average and below-average performers. Replacement-level is a useful concept for both sports, or neither. |
Great post...thank you for putting more concrete numbers on the analogy. |
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gabefarkas
Joined: 31 Dec 2004
Posts: 1313
Location: Durham, NC
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| Posted: Thu May 27, 2010 4:06 pm Post subject: |
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| schtevie wrote: | Dean, in a lawyerly sense, how can I or anyone disagree with this last sentence? Does money matter? Yes. Do replacement players cost money? Yes. Therefore replacement players matter. Yes. But there is little nutritional value therein for the debate at hand.
If an NBA franchise is going to field a team, it needs practice bodies, it needs insurance against injury to the best players, and it needs players to keep the players above them honest, and sometimes to humor the coaching staffs in their belief - true or not - that they can identify match-up advantages. All these functions call for replacement level players (and those slightly above. What is the agreed-upon definition for replacement players again?) If you need these functions fulfilled, you need warm bodies that cost money, and, on average, each NBA team grabs five out of the bottom 150 players who suit up.
These functions however are essentially independent of the valuation of the better talent and the expenditure of resources on them.
It is in this sense that explicitly introducing the concept of budget constraint (with all the byzantine, CBA bells and whistles and variation depending on franchise location and competitive standing) to the discussion is counterproductive. |
From what you wrote here, it seems you perceive the NBA as basically containing 2 classes of players. Essentially, from the way you describe them, they are the have's (who you refer to as the "better talent") and the have not's ("warm bodies"), where the item being possessed is playing time/skill/ability/etc.
Assuming I'm interpreting you correctly, I'm skeptical that the dichotomy is as clear as you describe it. Please let me know if I'm misrepresenting your viewpoint.
| schtevie wrote: | That I did not explicitly mention contingencies of injury (or, say, the impact of aging with a multi-year contracts) was of course only due to a desire to emphasize the essential, core point. But this aside, the replacement level still isn't required to "really understand the deal". Replacement level players are going to be on a team as a class, independent of the existence of starters, independent of players 6 through 10 (but wait, is the 10th player a replacement, or not? I cannot remember.)
One may decide if one has an injury-prone starter whose functions are a core part of the defense or offense, to invest a bit more in his insurance. (But are we then talking about a non-replacement player?) But the general decision to insure is not part of the rational calculation. That cost is sunk. |
Again, you seem to be referring to replacement players as a separate "class" of players. Is this correct?
(And again, apologies if I'm misunderstanding you.)
| schtevie wrote: | | HoopStudies wrote: | | schtevie wrote: | And just to emphasize the point, the motivation of this detour was the discussion of VORP in terms of the draft. Such an exercise perfectly illustrates the shortcomings. Every player in the draft, from the highly skilled lottery picks to the workhorses of the late second round are compared against a common imprecise composite. Again, to what gain?
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Draft picks, in particular, need to be evaluated against a replacement level because many are not that different from the easy-to-obtain free agent at replacement level. |
I am sure I am belaboring the point, but the draft is a different application, so on I go. I am not going to argue that, on average, late first round or second round picks don't end up that much different than replacement players. (DSMok1's lovely graphs clearly show this - again contingent upon agreement about what a replacement level player is. And as such, my preference would be to not muck up a graph presenting this information by subtracting each of these contributions from a notional replacement value. Let this information be somewhere in the title if at all.) However, the draft is different from other player transactions in that each pick has significant option value. You don't see teams trading draft rights for replacement players, which nicely summarizes my point. |
Call me daft, but could you help me understand how to reconcile the concepts in the two bolded statements? To me, it seems either the draft "illustrates the shortcomings" of VORP, or it's a different concept from the faultiness of VORP that you've pointed out. I'm not sure how it can simultaneously endorse and debunk VORP.
Also, regarding the statement about teams trading draft rights for replacement players, I would think at least one or two of the following would be considered replacement level by your definition above:
Randy Foye, Mike Miller, Etan Thomas, Darius Songaila, Oleksiy Pecherov, Ricky Davis, Marcus Banks, Mark Blount, Justin Reed, Wally Szczerbiak, Michael Olowokandi, Dwayne Jones, Gerald Green, Theo Ratliff, Ryan Gomes, Sebastian Telfair, Antoine Walker, Wayne Simien, Michael Doleac, Sean Singletary, Patrick Ewing Jr., Bobby Jackson, Donte Greene, Kurt Thomas, Brent Barry, Francisco Elson, Johan Petro, Chucky Atkins, Thabo Sefolosha, Mike Taylor, Ronald Dupree, Nicolas Batum, Joey Dorsey, Zarko Cabarkapa, Eddy Curry, Antonio Davis, Tim Thomas, Michael Sweetney, Jermaine Jackson, Omer Asik, Carlos Delfino, Mikki Moore, Kyle Weaver, Kareem Rush, Stanko Barac, Jason Smith, Daequan Cook, Mario Chalmers, Larry Hughes, Drew Gooden, Cedric Simmons, Ira Newble, Donyell Marshall, Aaron Williams, Radoslav "Rasho" Nesterovic, Matt Bonner, Eric Williams, Shawne Williams, Jackie Butler, Melvin Ely, Darnell Jackson. |
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schtevie
Joined: 18 Apr 2005
Posts: 412
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| Posted: Thu May 27, 2010 7:27 pm Post subject: |
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| gabefarkas wrote: | | schtevie wrote: | Dean, in a lawyerly sense, how can I or anyone disagree with this last sentence? Does money matter? Yes. Do replacement players cost money? Yes. Therefore replacement players matter. Yes. But there is little nutritional value therein for the debate at hand.
If an NBA franchise is going to field a team, it needs practice bodies, it needs insurance against injury to the best players, and it needs players to keep the players above them honest, and sometimes to humor the coaching staffs in their belief - true or not - that they can identify match-up advantages. All these functions call for replacement level players (and those slightly above. What is the agreed-upon definition for replacement players again?) If you need these functions fulfilled, you need warm bodies that cost money, and, on average, each NBA team grabs five out of the bottom 150 players who suit up.
These functions however are essentially independent of the valuation of the better talent and the expenditure of resources on them.
It is in this sense that explicitly introducing the concept of budget constraint (with all the byzantine, CBA bells and whistles and variation depending on franchise location and competitive standing) to the discussion is counterproductive. |
From what you wrote here, it seems you perceive the NBA as basically containing 2 classes of players. Essentially, from the way you describe them, they are the have's (who you refer to as the "better talent") and the have not's ("warm bodies"), where the item being possessed is playing time/skill/ability/etc.
Assuming I'm interpreting you correctly, I'm skeptical that the dichotomy is as clear as you describe it. Please let me know if I'm misrepresenting your viewpoint. |
My viewpoint is the opposite? It might appear that I am imposing a trichotomy, but that too isn't quite right. What I have tried to represent is that the value function is continuous-ish (as everyone believes?) You go from player n to n+1 in the rankings and the latter is a bit worse (pick your metric). Such that when you get to the bottom 300 and below, these are clearly players that move the scoreboard in the wrong direction.
The introduction of better and worse players in terms of class had only to do with the concept of substitutions. In theory, the top five (more or less) are starters, then when they get tired (or injured, or accumulate fouls) the next five in are the primary subs, then those that ride the end of the pine (eleven through however many else are suited up) are the corresponding substitutes, with true replacement players (on average) being a debatable fraction of these.
| gabefarkas wrote: | | schtevie wrote: | That I did not explicitly mention contingencies of injury (or, say, the impact of aging with a multi-year contracts) was of course only due to a desire to emphasize the essential, core point. But this aside, the replacement level still isn't required to "really understand the deal". Replacement level players are going to be on a team as a class, independent of the existence of starters, independent of players 6 through 10 (but wait, is the 10th player a replacement, or not? I cannot remember.)
One may decide if one has an injury-prone starter whose functions are a core part of the defense or offense, to invest a bit more in his insurance. (But are we then talking about a non-replacement player?) But the general decision to insure is not part of the rational calculation. That cost is sunk. |
Again, you seem to be referring to replacement players as a separate "class" of players. Is this correct?
(And again, apologies if I'm misunderstanding you.) |
Again, not really. I am saying that the replacement players (somehow defined) come from the bottom of the distribution, and these are expected to be the players at the end of the bench. But that is not point of the clause you cite. The point is that decisions about acquiring such secondary or tertiary substitutes should be fundamentally distinct from the appraisal of starters and even primary substitutes.
| gabefarkas wrote: | | schtevie wrote: | | HoopStudies wrote: | | schtevie wrote: | And just to emphasize the point, the motivation of this detour was the discussion of VORP in terms of the draft. Such an exercise perfectly illustrates the shortcomings. Every player in the draft, from the highly skilled lottery picks to the workhorses of the late second round are compared against a common imprecise composite. Again, to what gain?
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Draft picks, in particular, need to be evaluated against a replacement level because many are not that different from the easy-to-obtain free agent at replacement level. |
I am sure I am belaboring the point, but the draft is a different application, so on I go. I am not going to argue that, on average, late first round or second round picks don't end up that much different than replacement players. (DSMok1's lovely graphs clearly show this - again contingent upon agreement about what a replacement level player is. And as such, my preference would be to not muck up a graph presenting this information by subtracting each of these contributions from a notional replacement value. Let this information be somewhere in the title if at all.) However, the draft is different from other player transactions in that each pick has significant option value. You don't see teams trading draft rights for replacement players, which nicely summarizes my point. |
Call me daft, but could you help me understand how to reconcile the concepts in the two bolded statements? To me, it seems either the draft "illustrates the shortcomings" of VORP, or it's a different concept from the faultiness of VORP that you've pointed out. I'm not sure how it can simultaneously endorse and debunk VORP.
Also, regarding the statement about teams trading draft rights for replacement players, I would think at least one or two of the following would be considered replacement level by your definition above:
Randy Foye, Mike Miller, Etan Thomas, Darius Songaila, Oleksiy Pecherov, Ricky Davis, Marcus Banks, Mark Blount, Justin Reed, Wally Szczerbiak, Michael Olowokandi, Dwayne Jones, Gerald Green, Theo Ratliff, Ryan Gomes, Sebastian Telfair, Antoine Walker, Wayne Simien, Michael Doleac, Sean Singletary, Patrick Ewing Jr., Bobby Jackson, Donte Greene, Kurt Thomas, Brent Barry, Francisco Elson, Johan Petro, Chucky Atkins, Thabo Sefolosha, Mike Taylor, Ronald Dupree, Nicolas Batum, Joey Dorsey, Zarko Cabarkapa, Eddy Curry, Antonio Davis, Tim Thomas, Michael Sweetney, Jermaine Jackson, Omer Asik, Carlos Delfino, Mikki Moore, Kyle Weaver, Kareem Rush, Stanko Barac, Jason Smith, Daequan Cook, Mario Chalmers, Larry Hughes, Drew Gooden, Cedric Simmons, Ira Newble, Donyell Marshall, Aaron Williams, Radoslav "Rasho" Nesterovic, Matt Bonner, Eric Williams, Shawne Williams, Jackie Butler, Melvin Ely, Darnell Jackson. |
Here I think the confusion is semantic. By "different application" I was merely trying to draw a distinction between the notion of "replacement level" as the opportunity cost for "starting-level" players and that for draft picks. Starters are known quantities (more or less) as opposed to draftees. And they are "known" to be much more valuable than replacement players. Draftees, by contrast, aren't, but the rational belief that there is a potential upside confers value on them that makes them more valuable (until some draft cutoff point perhaps) than replacement players.
As for the data dump, the link gave me a headache. Can you summarize the data? In particular, can you identify where a draft pick (whatever round) was traded straight up for "known" replacement players? If so (and if commonly done) this is clear evidence against my argument that replacement players are not the relevant opportunity cost for draftees. But my impression is that such transactions are not common at all. |
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Mike G
Joined: 14 Jan 2005
Posts: 3605
Location: Hendersonville, NC
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| Posted: Fri May 28, 2010 7:29 am Post subject: |
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| DSMok1 wrote: | | schtevie wrote: |
... What are replacement level players? They are by definition the worst players in the league.
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If, during the season, LBJ is hurt and lost for the season, who takes his place on the roster? That is his replacement. The margin between LBJ and whoever took his place on the roster is the value of LBJ. Thus VORP.
.. |
Quite a divergence of opinion here. I am quite a bit closer to schtevie's definition (though player X might be still less good than player R).
DSMok1 suggests a VORP that changes by a player's situation, could change several times during a season/postseason, or could change daily. Suddenly and dramatically even (if your backup gets hurt).
When Byron Scott and Magic Johnson were hurt in the '89 Finals, Michael Cooper's importance increased hugely; as did backup-backups Tony Campbell and David Rivers. But such situational 'value' is so esoteric, it can hardly be applied to any different situation. It's like saying a guy has more value when he's hot, and less when he's in a slump. Of course, and so-what?
Most of the time, a starter is in fact replaced by someone quite a bit better than the 11th-thru-15th player definition of RP -- the truly 'replaceable' players on the roster. There's a competition in acquiring the 'best of the rest' 3rd-string level guys.
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DSMok1
Joined: 05 Aug 2009
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| Posted: Fri May 28, 2010 10:33 am Post subject: |
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| Mike G wrote: |
DSMok1 suggests a VORP that changes by a player's situation, could change several times during a season/postseason, or could change daily. Suddenly and dramatically even (if your backup gets hurt).
When Byron Scott and Magic Johnson were hurt in the '89 Finals, Michael Cooper's importance increased hugely; as did backup-backups Tony Campbell and David Rivers. But such situational 'value' is so esoteric, it can hardly be applied to any different situation. It's like saying a guy has more value when he's hot, and less when he's in a slump. Of course, and so-what?
Most of the time, a starter is in fact replaced by someone quite a bit better than the 11th-thru-15th player definition of RP -- the truly 'replaceable' players on the roster. There's a competition in acquiring the 'best of the rest' 3rd-string level guys. |
Everyone's VORP in actuality depends on their context. Some teams can handle a loss better than others.
What we need is a context-neutral VORP, perhaps the value of the player to a league-average team, with a league-average roster makeup. I'm not sure how to do this, however. It would approximate the player's value on the free-agent market...
Here's what I mean: Brook Lopez is worth quite a lot to the Nets--if he goes out, they are forced to play very bad players. However, if he were on, say, the Cavs, they would not lose much if he went out. So in context, he's "worth" more than he would be worth on the open market. Does that make sense? Or am I turned around? |
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Mike G
Joined: 14 Jan 2005
Posts: 3605
Location: Hendersonville, NC
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| Posted: Fri May 28, 2010 10:59 am Post subject: |
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| DSMok1 wrote: |
... Or am I turned around? |
Well, the Pythagorean wins-created model would say a player on a bad team creates fewer wins than the same guy on a better team. This is because his estimated point differential creation (vs the bad team's opponents) has been exaggerated by a large exponent (like 14).
The hue and cry for "context-neutral VORP" about 6 years ago led to the invention (or discovery) of eWins -- Equivalent Wins created for an average team. I've refined it many times, but as far as I know, nobody else has attempted anything similar.
It may be that had they managed to trade Shaq and Z for B-Lopez (maybe Hickson, too), the Cavs are still rolling.
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36% of all statistics are wrong |
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gabefarkas
Joined: 31 Dec 2004
Posts: 1313
Location: Durham, NC
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| Posted: Fri May 28, 2010 10:25 pm Post subject: |
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| schtevie wrote: | | My viewpoint is the opposite? It might appear that I am imposing a trichotomy, but that too isn't quite right. What I have tried to represent is that the value function is continuous-ish (as everyone believes?) |
You had previously written the following:
"If an NBA franchise is going to field a team, it needs ... [list of items] ... All these functions call for replacement level players "
"These functions however are essentially independent of the valuation of the better talent and the expenditure of resources on them. "
To me, if one defines a list of criteria and activities for a certain group of players (call them Group R), then excludes another distinct group of players (call them Group S) from consideration in these criteria, and then defines the activities of Group R as "independent of the valuation" of Group S, that seems like a pretty clear dichotomy.
| schtevie wrote: | You go from player n to n+1 in the rankings and the latter is a bit worse (pick your metric). Such that when you get to the bottom 300 and below, these are clearly players that move the scoreboard in the wrong direction.
The introduction of better and worse players in terms of class had only to do with the concept of substitutions. In theory, the top five (more or less) are starters, then when they get tired (or injured, or accumulate fouls) the next five in are the primary subs, then those that ride the end of the pine (eleven through however many else are suited up) are the corresponding substitutes, with true replacement players (on average) being a debatable fraction of these. |
I realize you likely chose 300 as an arbitrary cutoff, but again it's introducing a differentiation point.
| schtevie wrote: | | gabefarkas wrote: | | schtevie wrote: | That I did not explicitly mention contingencies of injury (or, say, the impact of aging with a multi-year contracts) was of course only due to a desire to emphasize the essential, core point. But this aside, the replacement level still isn't required to "really understand the deal". Replacement level players are going to be on a team as a class, independent of the existence of starters, independent of players 6 through 10 (but wait, is the 10th player a replacement, or not? I cannot remember.)
One may decide if one has an injury-prone starter whose functions are a core part of the defense or offense, to invest a bit more in his insurance. (But are we then talking about a non-replacement player?) But the general decision to insure is not part of the rational calculation. That cost is sunk. |
Again, you seem to be referring to replacement players as a separate "class" of players. Is this correct?
(And again, apologies if I'm misunderstanding you.) |
Again, not really. I am saying that the replacement players (somehow defined) come from the bottom of the distribution, and these are expected to be the players at the end of the bench. But that is not point of the clause you cite. The point is that decisions about acquiring such secondary or tertiary substitutes should be fundamentally distinct from the appraisal of starters and even primary substitutes. |
So they are "fundamentally distinct", but this isn't the same as defining them as a separate class?
| schtevie wrote: | | gabefarkas wrote: | | schtevie wrote: | | I am sure I am belaboring the point, but the draft is a different application, so on I go. I am not going to argue that, on average, late first round or second round picks don't end up that much different than replacement players. (DSMok1's lovely graphs clearly show this - again contingent upon agreement about what a replacement level player is. And as such, my preference would be to not muck up a graph presenting this information by subtracting each of these contributions from a notional replacement value. Let this information be somewhere in the title if at all.) However, the draft is different from other player transactions in that each pick has significant option value. You don't see teams trading draft rights for replacement players, which nicely summarizes my point. |
Call me daft, but could you help me understand how to reconcile the concepts in the two bolded statements? To me, it seems either the draft "illustrates the shortcomings" of VORP, or it's a different concept from the faultiness of VORP that you've pointed out. I'm not sure how it can simultaneously endorse and debunk VORP.
Also, regarding the statement about teams trading draft rights for replacement players, I would think at least one or two of the following would be considered replacement level by your definition above:
Randy Foye, Mike Miller, Etan Thomas, Darius Songaila, Oleksiy Pecherov, Ricky Davis, Marcus Banks, Mark Blount, Justin Reed, Wally Szczerbiak, Michael Olowokandi, Dwayne Jones, Gerald Green, Theo Ratliff, Ryan Gomes, Sebastian Telfair, Antoine Walker, Wayne Simien, Michael Doleac, Sean Singletary, Patrick Ewing Jr., Bobby Jackson, Donte Greene, Kurt Thomas, Brent Barry, Francisco Elson, Johan Petro, Chucky Atkins, Thabo Sefolosha, Mike Taylor, Ronald Dupree, Nicolas Batum, Joey Dorsey, Zarko Cabarkapa, Eddy Curry, Antonio Davis, Tim Thomas, Michael Sweetney, Jermaine Jackson, Omer Asik, Carlos Delfino, Mikki Moore, Kyle Weaver, Kareem Rush, Stanko Barac, Jason Smith, Daequan Cook, Mario Chalmers, Larry Hughes, Drew Gooden, Cedric Simmons, Ira Newble, Donyell Marshall, Aaron Williams, Radoslav "Rasho" Nesterovic, Matt Bonner, Eric Williams, Shawne Williams, Jackie Butler, Melvin Ely, Darnell Jackson. |
Here I think the confusion is semantic. By "different application" I was merely trying to draw a distinction between the notion of "replacement level" as the opportunity cost for "starting-level" players and that for draft picks. Starters are known quantities (more or less) as opposed to draftees. And they are "known" to be much more valuable than replacement players. Draftees, by contrast, aren't, but the rational belief that there is a potential upside confers value on them that makes them more valuable (until some draft cutoff point perhaps) than replacement players. |
If we eliminate the belief that you "don't see teams trading draft rights for replacement players", then that seems to poke a hole in the argument...
| schtevie wrote: | | As for the data dump, the link gave me a headache. Can you summarize the data? In particular, can you identify where a draft pick (whatever round) was traded straight up for "known" replacement players? If so (and if commonly done) this is clear evidence against my argument that replacement players are not the relevant opportunity cost for draftees. But my impression is that such transactions are not common at all. |
...but instead of giving consideration to that concept, you dismiss my research as a mere "data dump". If something about the aesthetics of the site gave you a headache, you should direct the complaint to APBR member Frank Marousek (frank@prosportstransactions.com), whose tireless efforts compiled the data that went into it.
Either way, I'll simplify it for you:
(1) The link leads to a list of all 2009 NBA Draft Pick Transactions.
(2) The list I provided is of players involved in these transactions.
(3) You define replacement players as "practice bodies", "insurance against injury to the best players", "players to keep the players above them honest", and "warm bodies that cost money".
(4) You also claim that teams don't trade "draft rights for replacement players".
I contend that several, if not most, of the players in #2 fulfill the roles defined in #3. Provided #1 is true (which, by definition, it is), this invalidates your claim in #4. |
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