Nylon Calculus: Tracking the imbalance between conferences
Disney World or Disneyland? Biggie or Tupac? Hardee’s or Carl’s Jr? We’re talking about East versus West, here!! And this weekend at the physical manifestation of our nation’s metaphorical East-vs.-West divide — in New Orleans, the terminus of the mighty Mississippi River — the NBA All-Star Game will settle each of these enduring feuds and so many more.
Just kidding.
The All-Star Game won’t settle any of that. It won’t even tell us which is the superior conference of the NBA. But I will…at least, I’ll adjudicate that last bit about which conference is better. I’ll leave it to you to decide who makes the better burger.
Tukey’s pocket test
Two years ago, the Russell Westbrook-led Oklahoma City Thunder finished eight games above 0.500 (45-37), but failed to make the Western Conference Playoffs. On the other side of the country, the Mason Plumlee-led Brooklyn Nets finished six games below 0.500 (38-44), but got their shot in the postseason anyways. It was arbitrary. It was unfair. Cue the [flock of wah-wahs] emoji.
In the name of aggrieved ninths seeds everywhere, innovative plans for geography-free tournament brackets were hatched…and…ignored. NBA life continued along the same East-West axis as it always had before. And then suddenly, everything was fine. Last year, the eighth seed from the East (44-38, Detroit Pistons) had a slightly better record than the eighth seed in the West (41-41, Houston Rockets). This season the two potential eight seeds are looking pretty comparable once again.
But does that mean the conferences are actually evenly matched, this year? I believe a more useful indicator of the inter-conference balance of power is Tukey’s pocket test. Not familiar with Dr. J.W. Tukey’s work in the 1959 issue of Technometrics? No problemo. Let me explain.
It’s actually a totally intuitive test. It’s the way we’re already evaluating the relative strengths of the two conferences, whether or not we’re doing it consciously. It’s like this: line up all of the teams in the NBA from best-to-worst. Count the number of consecutive Western Conference teams at the top of the list and add the number of consecutive Eastern Conference teams at the bottom of the list and that is Tukey’s score.
Using the Simple Rating System — a way to rank teams based on average margin-of-victory and strength-of-schedule — we can calculate Tukey’s score for this season. By this measure, the top three resumes in the league all belong to teams in the West — the Golden State Warriors, the San Antonio Spurs, and the Houston Rockets — whereas the bottom three teams in the league are all from the East — the Philadelphia 76ers, the Orlando Magic, and the Brooklyn Nets. So, we just add up 3 + 3 for a Tukey’s score of 6.
Now, let’s calculate the Tukey’s score for every season since the NBA-ABA merger to chart how the balance of power has tilted over time.
Simple Rating System score for each NBA team in the Eastern (Green) and Western (purple) Conference by season since the NBA-ABA merger; the best and worst teams are highlighted and the corresponding Tukey’s score is plotted.
So, according to Prof. Tukey, the current era of western domination began in 2013. As has been the case this season, it’s been the Warriors, Spurs, and Rockets holding it down for the West lately; but the Los Angeles Clippers, the Oklahoma City Thunder, and the Portland Blazers have helped, too. In 2014, all six of those teams had higher SRS scores than the Miami Heat, the best team in the East. That lopsidedness resulted in a Tukey’s score of 8, the largest of the post-merger era.
The current period of inter-conference imbalance is probably only matched by one previous run, from 1999 to 2007, when the West was once again the dominant side. The Tukey’s scores from the two eras are comparable, but in addition to the regular season disparity, the 2000s also saw a preponderance of championships for the West’s best teams (as indicated by the gold rings in the plot above). During those nine years, the West won seven rings collectively — three for the Lakers and four for the Spurs — with only the upstart Pistons and Heat stealing titles for the East.
Between these two recent periods of ascendancy for the West, the East was buoyed by LeBron James and his teams, from 2008-2012, first as a player with the Cleveland Cavaliers and subsequently with the Heat. The Boston Celtics, the Chicago Bulls, and the Orlando Magic also peaked in the East during these years.
From 1979 to 1998 the opposite pattern was apparent: the best teams in the league played in the East. There were Michael Jordan’s six-time-champion Bulls from 1991 to 1998. Before that, there were the Celtics, the 76ers, and the Pistons — all champions in the 1980s. And the primary counterbalance to eastern supremacy during this era was the Lakers.
Star power
We’ve demonstrated that, over the last two decades, many of the best teams in the league have been in the West; not coincidentally, most of the league’s biggest stars have played there, too.
Every season since 1999, the Western Conference has had more representatives on the All-NBA teams than the Eastern Conference, sometimes overwhelmingly so. For example, in 2015, only three players from the East — LeBron James (1st team), Pau Gasol (2nd team), and Kyrie Irving (3rd team) — made the All-NBA teams. The remainder of the league’s biggest stars were from the Western Conference — Stephen Curry, Russell Westbrook, James Harden, Chris Paul, Jimmer Fredette…all of them. The stars shined brighter in the western sky during the 2000s, too — Shaquille O’Neal, Kobe Bryant, Tim Duncan, Dirk Nowitzki, Steve Nash — all of the league’s best players were from the West.
Prior to 1999, the ratio of East:West All-NBA players was more balanced, with each conference fielding the majority for several individual seasons. For example, in 1987, the East had seven of the ten All-NBA players (there were only two five-player teams at that point in time): Michael Jordan, Larry Bird, Isiah Thomas, Charles Barkley, Moses Malone, Dominique Wilkins, and Kevin McHale. The West had only three representatives: Magic Johnson, Hakeem Olajuwon, and Fat Lever.
The number of All-NBA players selected from the Eastern (Green) and Western (purple) conferences by year.
So, what does all of this mean for the All-Star Game? Well, this weekend, many of the biggest stars will once again be in the West and the biggest storyline will be the continuing bitterness between Western Conference All-Stars — Russell Westbrook and Kevin Durant. The trash-talking, head-butting, cupcake-eating showdown between Westy and KD’s Warriors in Oklahoma on Saturday was less than cordial; so, it’s safe to assume all eyes will be on the western players again in New Orleans.
Next: NBA Draft Big Board: Early February update
Still, with rising stars like Joel Embiid in Philadelphia, Kristaps Porzingis in New York, and Myles Turner in Indiana, the East has reason to be optimistic about the future. Perhaps these guys can tip the balance of power back towards the East sometime soon.