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.