In a business analytics course in my sports MBA program, we learned about a concept called cluster analysis in which a set of objects are grouped so that the objects within each group are more similar than objects in different groups.
I applied that newfound knowledge to an NBA dataset I created that takes into account a team’s regular season offensive rating, defensive rating, offensive rebound rate, defensive rebound rate, true shooting percentage, assist ratio, team turnover percentage and pace to group teams covering 12 seasons of NBA play from 2000-13. The lockout-shortened 2011-12 season was not included because 16 fewer regular season games were played.
I used Ward’s Method to break the data into 10 clusters and found one 31-team cluster that can essentially be called the “Suns” cluster because it features six consecutive Phoenix squads during the heart of the Nash Era from 2004-10. Perhaps it should be no surprise that the three Dallas Mavericks teams from 2001-04 also slot into this cluster since Nash was at the controls of those teams as well.
One of the most interesting aspects of cluster analysis is seeing which other teams the SSOL Suns are grouped with. Since those Phoenix teams put up such consistently incredible offensive efficiency/true shooting numbers, it should be no surprise that they ended up in the same cluster. The Suns’ cluster also includes a host of elite offensive teams such as the 2006-09 Lakers, the ’09-13 Thunder, the ’04-05 Kings, the ’12-13 Clippers and Warriors and the ’06-10 Jazz. The ’07-09 Celtics and ’04-05 Heat are the East’s only representatives in the cluster, which speaks to the stylistic differences between the conferences.
Looking at the dataset as a whole, many clusters possess the same team in consecutive years but few teams had such long runs of belonging to the same cluster. The Atlanta Hawks — who missed the playoffs every season from 2000-07 — held the only seven-year run, whereas the Suns’ perennial Western Conference foes the Dallas Mavericks and San Antonio Spurs each had a six-year streak of being in the same cluster from 2006-13 with the lockout season perhaps preventing a seven-year run. That speaks to the remarkable consistency of the SSOL Suns to maintain such a similar level of play throughout a six-season stretch that could only be matched by their rivals of that era from Dallas and San Antonio. The Hawks’ run of consistency, meanwhile, was not in the way a team hopes to be consistent.
The Suns’ cluster outscored opponents by 5.32 points per 100 possessions, a clear leader among clusters with the next best cluster at 4.40. It is the best offensive cluster with a 108.4 offensive rating and a true shooting percentage of 56 percent. The Suns’ cluster was statistically significantly better in terms of offensive rating than all but one cluster and statistically significantly ahead of all but two in true shooting (one being the Spurs/Mavs cluster).
Defensive rating (surprise, surprise) was a different story, as the Suns’ cluster ranked fifth out of the 10. They were also seventh in offensive rebounding percentage but second in pace, so you can see how this is a very Suns cluster.
This Suns’ cluster averaged 53.7 wins a season, the best average of any cluster and a mark that was statistically significantly better than all but two clusters (yes, one being the Spurs/Mavs one). These teams led all clusters by reaching the playoffs 94 percent of the time (the Suns’ 46-win 2008-09 team was one of two outliers along with the 43-win Rockets from ’10-11), so this offensive-oriented cluster was the best in the regular season.
Thanks in large part to the Suns’ three conference finalists, this cluster reached the NBA’s semifinals 35 percent of the time, good for second behind a cluster that did so 36 percent of the time. However, like the Nash Era Suns, that’s where the cluster hit a roadblock. Even with all the playoff teams, it dropped to fourth in Finals appearances with 10 percent and third in championships with 6 percent. The 2007-08 Celtics and the ’07-08 and ’08-09 Lakers were the only teams to reach the Finals from the Suns’ cluster. The Mavs/Spurs cluster led in Finals appearances with 18 percent and was tied for the lead in titles at 9 percent.
Ultimately, this analysis provides an interesting way to group teams and matches history as well. After all, the six SSOL-era Suns squads certainly belong together in an elite scoring/shooting cluster that led in net rating but did not enjoy as much playoff success as some of the other groupings of top teams.
Tags: Cluster Analysis