Team Positional Production Allocation… or Something
Posted by Neil Paine on August 7, 2009
A quick post/data dump for Friday... When I was putting together some of the Win Shares-based lists we've been posting recently, I wondered how heavily each team relied on their frontcourt and backcourt, and whether or not that correlated to success. So, first I added up WS by a team's guards and their non-guards, making each into a percentage. Here are the most guard-heavy teams in terms of production this decade:
Overall, the correlation between Pct_G and total team WS was 0.091, which is not very big -- but at least it's positive.
Now, the most frontcourt-dependent teams:
The correlation between Pct_FC and team success is actually -0.091, meaning the more reliant you are on your frontcourt for production, the more you actually tend to lose games. However, these correlations are truly microscopic in both cases, which means there is no real relationship between a team's allocation and its success. (We'll see later that balance is by far the more important determining factor in team wins.)
Anyway, I wanted to look at this one other way, since our positional designations are pretty generic and aren't always the most accurate in the world. The 40th percentile height of every player from 99-2000 to 2008-09 was 78 inches, so I classified every player 6'6" or shorter as "smalls" and 6'7" or taller as "bigs", just to add another angle that our positions were perhaps not picking up. Here were the teams most centered around their "smalls":
Some crossover there with our guards table, except where C-Spoon seems to be concerned. The correlation between smalls' production and Win Shares was 0.094, essentially the same as we found for the guards. And that means it's essentially the same for the "bigs":
Obviously, the correlation between "big" production and total team WS is -0.094, in keeping with our earlier results with the positional designations.
Finally, I calculated a metric called "balance", which is simply the difference between a team's allocation and the "ideal" allocation of 2/5 of the team's WS going to guards/smalls and 3/5 going to bigs/frontcourt players. The correlation between "balance" and WS is essentially 0.3 for both the positional study and the height-based one, confirming the conventional wisdom that a team with balanced production between its backcourt and frontcourt will tend to do the best. This is still not a major correlation by statistical standards, mind you, but it is much higher than the correlation we were seeing for the teams biased toward either bigs or smalls.
What does any of this mean? Well, again, it's best to balance your production between your frontcourt and your backcourt, your bigger players and your smaller ones. But, it appears that there's a very slight trend over the last decade that says teams who rely on their guards and smaller players tend to win a few more games over the course of a season. This makes sense, given that the league spent most of the Oughts trying to tip the advantage in favor of perimeter scorers with modifications to the rules on hand-checking and more liberal foul calls on drives in general.
August 7th, 2009 at 3:08 pm
Love the site. But did Artest play any guard for Sacto? Every box I've checked has him at SF. And the only time I can remember him getting extensive time at guard was his rookie year for the Bulls.
August 7th, 2009 at 3:41 pm
Wouldn't the fact that the two most dominant teams of the decade do not appear on any list seem to negate this premise? San Antonio and LA have won 8 of the last 11 titles.
August 7th, 2009 at 3:42 pm
@KneeJerkNBA
Yeah but SF is almost (basically) a guard. Depending on the offense it definitely can be. I think they were just taking a little liberty.
August 7th, 2009 at 3:47 pm
@Ben Smith
The fact that they don't appear just confirms that balanced teams have the most success, which we kind of already proved with the very low correlations between wins and a heavy allocation in either direction.
August 7th, 2009 at 3:53 pm
As far as positions go, yeah, they're not always accurate to each specific season. When a player is considered one position, we don't really change it across their career even if they played a different position in some seasons. Artest has played both G and F, but he's considered a G here for his entire career. That's why I threw in the height thing too, just to catch guys that might be incorrectly assigned a position. Positions are so fluid in basketball that any designation is going to be arbitrary anyway.
August 7th, 2009 at 5:03 pm
I guess it's not surprising that being overbalanced w/ bigs or smalls is not a good formula for winning.
It's a corruption of the idea behind the post, but I would be very interested to see what WS has to say about the best Trios in NBA history. I'd love to see how Magic, Worthy, Kareem stacks up against Timmy, Manu, Parker or Jordan, Pippen, Grant and KG, Allen, Pierce. Or maybe less successful trios who have zero help would dominate the list like Run TMC and the current Wiz (but I doubt it).
August 7th, 2009 at 5:40 pm
However, these correlations are truly microscopic in both cases, which confirms that a team with balanced production between its backcourt and frontcourt will tend to do the best.
Am I missing something? I don't think that's confirmation at all. I accept that (a) there is essentially no correlation, and that (b) more balanced teams are probably the best (based on other evidence), but don't see at all how (a) leads directly to (b). If there were truly no correlation, then it wouldn't matter how frontcourt/backcourt-oriented you were, right? (the main problem here being the use of a linear model, which logically does not reflect reality)
August 7th, 2009 at 6:45 pm
Thanks for the catch, I knew I forgot something in this post -- I also wanted to report what the correlation between "balance" (the difference between the ideal distribution, 2/5 guards and 3/5 FC, and the team's actual allocation) and wins was: 0.31, which while still small by statistical standards, is much higher than the 0.09 and -0.09 we reported for the guard-heavy and big-heavy teams. That's the missing piece; you're right that a correlation of 0 simply means no relationship in either direction (you could have a lot of wins with a guard-heavy team or few wins, but there's no relationship between wins and allocation), but when compared with the other correlation for "balance", we see confirmation that balance is far more correlated with success than heavy overbalance in either direction. I've changed the post to reflect this.
August 9th, 2009 at 12:40 pm
Yeah...just saw that it was odd that Artest was counted as a guard for Sac in '07 while Butler was counted as a big for Was this past season - though both played similar roles on their respective teams. I know this isn't an exact science, but I'd be interested in seeing what the numbers would be if Artest was counted as a frontcourt and Butler as a backcourt player.