mystic wrote:schtevie, have you ever heard of a thing called confirmation bias? Just asking, because all your posts have exactly that bias. You are trying to "prove" your idea and with that you are looking only for evidence which is supporting your idea. And whenever something is not exactly fitting in, you are interpreting it in a way that it either is supposed to be not meaningful or that it even can be twisted to fit into your idea.
If you wish to do more than parrot "confirmation bias", it would be helpful to provide particular evidence about its magnitude (never mind the sign).
The entire point of this post was to determine the extent to which "analytics" has had
practical effect in the NBA. Not whether it ever provided interesting and true information (it surely has, and we can talk about that); but whether such information has ever brought "significant" competitive advantage, on net, over time. Toward that end, the historical analysis necessarily must begin with the Dallas Mavericks, for all the reasons that have been repeated. Perhaps there is another club to look at, as well, but none that so fully meets the criteria as the Mavs.
So, in determining the possible effect of "analytics", the first step is deciding upon an analytical framework for appraising competitive success. I chose (R)APM, which is at least internally consistent in that something along these lines is the same basic framework the franchise in question uses.
The next step then is to subtract out the contribution of all "non-analytic" inputs. It seems to me that initial talent endowments are an obvious and uncontroversial debit. Mark Cuban inherited Dirk Nowitzki. End of that story, really, unless one wishes to argue that some significant fraction of Dirk's dirkness is owed to Mark Cuban's special sauce. (What is an interesting, separate, potential line of inquiry: whether players when on the Mavs were better, in RAPM terms, taking into account aging effects, than when not.)
And as for "confirmation bias" on this account, to the extent that it exists, it almost surely cuts the other way. As we are told, RAPM biases estimates to the mean, and I suspect that an unbiased, APM estimate, over the same eleven years, would show DN's contribution to have been slightly more than the +6.9 over the years in question.
The next "non-analytic" input to subtract is positive draft surprises. This is a fair debit, conceptually, but one can disagree about its measure. As for whether the dread "confirmation bias" horribly distorted the picture I painted is for the reader to decide. My intent was to fairly represent and account for this factor. If the gentle reader wishes to attribute the success of Josh Howard, in full, to the foresight of the Mavs front office, as opposed, in the other extreme, entirely to luck, fine. But that wouldn't be right either. If so, Marc Gasol and not Nick Fazekas would have been a Mav (and with the Spurs, Manu Ginobili would have been taken in the first not second round, and Popovich would have moved heaven and earth to move up in the draft order).
So, the specific issue at hand is what portion of JH's +1.1 contribution shouldn't have been subtracted. Can it really be that large? If so, this implicit assumption is that drafting is a precise science, which we all know not to be remotely true, right? And then, for consistency, what about adding back a bit of JH's RAPM undervaluation with respect to APM? Do we have much in the way of confirmation bias to this point? And which sign is it, again?
But I digress, if it makes one happier, consider the argument as being about the practical effect of analytics, net of initial endowments and lottery success.
So, where does that leave things? Well, once you have the long-term team performance net of the debited inputs, account needs to be taken of all possible other explanatory factors. And I think I was being all-inclusive in summarizing these as aging and injury effects. Is there another category? If so, please advise. And if there is confirmation bias in the way I handled these issues, feel free to identify it. Specifically:
* Please identify the excess injuries that the Mavs faced over the ten/eleven years in question, and it is the excess that matters. I am quite confident that you cannot, but you can try. And as noted, again, I think my "confirmation bias" cuts the other way. My reading of the tables suggests to me that the Mavs were likely less injured than the average NBA team.
* Please identify how I might have mishandled the discussion on aging effects. I provided an estimate based on Daniel's Adv. SPM approach which suggests an upward hill to climb, then contrasted this with my calculation based on some of Jeremias' recent RAPM data, which suggests that the hill could well have been flat. I chose the latter (tentatively) for the reasons stated, and let me just say that I look forward to any future estimates that will identify the sign and magnitude of this confirmation bias.
Taking all these explicitly noted and discussed factors into account (again, lower-bound initial endowments, lottery "luck", the dearth of excess injuries, and a possible peak age of 28 or above) and you get the net contribution (in an RAPM framework) of the Mavs "supporting cast" to be approximately 0 (-0.3).
So, the question then turns to whether 0 (conditional on all that was explicitly stated) is a big number (or an awesome one...)
mystic wrote:The average supporting cast (team without the respective best player) is cleary below 0, I calculated it to be around -2.5. And that includes the 2nd best player. If you would remove the two best players and you come up with a supporting cast of 0, the job done by the management can be considered really great.
And then again, the salary comparison is not useful, because the CBA is designed to make it more expensive for better teams. That should make it possible that worse teams can get better more quickly in order to have some sort of competitive balance. You are still ignoring that fact.
Again, I am very interested in seeing persuasive evidence that "analytics" had significant, positive impact on the Mavs' competitiveness over the eleven year stretch in question. Let's say, in that regard, that I share your confirmation bias.
Toward that end, identifying the correct "supporting cast" baseline is the first step. But ultimately, salary considerations must be taken into account: it is an input into the competitiveness production function, and cannot be ignored. But from these and previous remarks, I get the impression that you are unwilling to admit that Mark Cuban's money had anything to do with the Mavericks competitive fortunes. Very strange. Confirmation bias, perhaps?
And finally, about the awesomeness of 0 (whether it be a big or small 0), maybe there is some value in elaboration. Again, historical context is everything. This was a time (the only time, one never to be repeated) when such an informational advantage was available to a single franchise. With every realized transaction, the Mavericks had a huge advantage over (almost) every other team in the league. On each, there must have been a reasoned belief that they would get the better of it, in terms of +/-. And if each transaction (and there were many of them over 11 years) yielded, in expectation, a non-negative return, it is in this context that I find a final tally of (approximately) 0 kind of awesome.