hoopstudies wrote:Berri's method is fully laid out and available. You can replace his player metric with whatever you like and run the analysis. It ain't easy, but not much is easy in evaluating coaches.
Dean, is there a link to Berri's coaching stuff you might have on hand? I don't recall it, from back in the day, as having been terribly interesting. There are two general approaches one can take. One is to estimate the direct contributions (what requires granular, "inside" information and what seems to be the basis of your faith in Karl) and the other is to treat the coaching contribution as a residual, having subtracted the contributions of players (the basis of my estimate of Karl's Denver swansong). Me, I have a bit more faith in the latter, generally (especially over many years of observation) as there is a great risk of spurious attribution of success/failure in the former.
Funny you should have mentioned this article. Earlier today I had begun to slog through it, but just couldn't keep reading, only revisiting and finishing it upon your prompting. And as for me (my conclusion ain't based on anything Berri ever said) I don't disagree with the Kerr piece, rather it well illustrates the point that there is an incredible desire in the media and population at large to celebrate "Coaches and Coaching" but when you scratch just a bit below the surface, their actual effect, numerically, when proper context is offered, is so much smaller than the rhetoric implies.
hoopstudies wrote:I would strongly disagree with any conclusion that says that coaches don't matter. If you have one coach who does things in an analytical way and another that doesn't - which would you think you'd want to work with in order to get wins?
Since you brought up the instantaneous transformation of the GSW under Kerr, as related in this ESPN feature story, let's consider the facts, in terms of the framework I previously provided: looking at how well 2013-14 plus-minus estimates, plus aging effects, anticipated the strength of Kerr's first team in 2014-2015.
Using 2013-14 RPM for as many as players as possible (then filling the gap with xRAPM and rookie estimates of -3.0) adding aging estimates (from the graphs here: viewtopic.php?f=2&t=8308&hilit=aging
) and utilizing actual 2014-15 minutes, what I get is and estimated GSW Offensive Efficiency of +2.1, a Defensive Efficiency of 5.7, for a Total of +7.8. This compares to an actual performance of +6.0, +4.2, and +10.2.
And from this, we infer a "Kerr Effect" of: +3.9 on Offense, -1.5 on Defense, and +2.4 overall.
Now, +2.4 is not bad. In fact, it is good! But what does it mean and what is the story behind it? Well, what we learn from the article is that his big innovation, elaborated over charcuterie, is that isolation basketball is inefficient! (By the way, when did this Eureka! moment come to our common awareness on this little forum?) But fairness is due, he surely is owed congratulations for improving his team's performance above baseline by +2.4 points per 100 possessions. Except...he's not. This is the fallacy of hagiography. This overall improvement of +2.4 isn't relative to a baseline of zero; it's relative to the contribution of Coach Mark Jackson. And this may be a zero baseline, but it may also be quite negative. And, it's a one-off.
But fairness is due only up to a point. One needs to take a cold, hard look at what potential "Coaching Contribution" really is. In this instance (as in a the sadly small number of instances where one can find "exceptional performances" in individual coaching seasons, where the gains are straightforwardly attributed to the painfully obvious opportunities afforded by increased three-point shooting) it is a one-off realization of on-court talent potential by eliminating its previous misutilization.
So, yes, coaching "matters", but it is best understood as a zero-sum enterprise, essentially independent from player contributions, and in a "perfectly competitive" world (where the drag of fraternal, coaching ideology and fanboy owners had zero effect and best practice would be rapidly adopted) the range of coaching contributions would be very small indeed.
And a final note about the risks of misattribution of coaching input: it is striking as a recent "historical" matter, how exceptional coaching has been attributed to historically successful teams and those only. This is a curious and counterintuitive empirical phenomenon; we all know that there have always been truly great players on mediocre and occasionally below-average teams. But not so with coaching, apparently... I encourage folks to go back into the googles and see the frequency with which Phil Jackson's name pops up as the coach uber alles. Does that conclusion ring true at all with the passage of Knick time?
Coaches are considered "great" primarily because they are on very successful teams whose success is overwhelmingly determined by player talent endowments, and a bit of luck helps too. (And adding the Knicks to one's resume changes all that right quick.)