San Antonio has had a roster continuity percentage lower than 75 percent in just three seasons since 1998-99. (AP Photo/Darren Abate)

With the 2014-15 NBA season firmly in the rear-view mirror, attention now shifts to the inevitability of offseason roster fluctuation. Every team has a watershed moment at the conclusion of each season: What will the team look like on opening night next season? Who will we draft and what does that mean for the future of the player currently in that position? Will a key veteran cog be shipped off elsewhere?

For any fan driven by an ardent desire for competitive success, keeping the roster intact should be more enticing than it’s made out to be.

Basketball-Reference recently unveiled a roster continuity metric, which calculates the percentage of a team’s regular season minutes that were filled by players from the previous season’s roster. By looking at the data, it’s evident that roster continuity is correlated to regular season success. Over the past three seasons, roster continuity has played a pivotal role in teams qualifying for the playoffs. Just three teams — 2014-15 Cleveland Cavaliers, 2014-15 Dallas Mavericks and the 2012-13 Houston Rockets  — made the postseason with less than 40 percent roster continuity. Meanwhile, 44 percent of playoff teams had a roster continuity percentage higher than 70, including seven this season.


Of the 10 teams with the highest roster continuity since the 1952-53 season, just two won championships, but each qualified for the postseason. Conversely, of the 10 teams with the lowest roster continuity, all but one—the 1997-98 Cleveland Cavaliers—made the playoffs, and they were eliminated in the first round.

Unsurprisingly, roster continuity is higher among teams that qualified for the Western Conference finals than teams that qualified for the Eastern Conference finals. The Western Conference is considered the more potent conference of the two: 12 of the last 17 NBA champions hailed from the West, and four Eastern Conference teams with losing records qualified for the playoffs since 2012-13 while four Western Conference teams with .500 records or better have missed out on the playoffs in that same time frame. The average roster continuity of teams in the Western Conference finals the past three seasons is 77.5 percent, while the average roster continuity of teams in the Eastern Conference finals is 75 percent; the implication being that a more stable roster is necessary for success in the dominant conference.


No season perhaps better represents the notion that outliers will exist in every data set quite like this one: Golden State and Houston met in the Western Conference finals, with a combined average roster continuity of 64 percent—a substantial drop from the 84.3 percent average of the 2012-13 and 2013-14 Western Conference finals matchups. Golden State won the NBA title with 80 percent of its regular season minutes filled by someone from the 2013-14 roster; Cleveland, on the other hand, went six games with the now-defending champs after just 39 percent of its minutes—the third lowest roster continuity percentage in the league—were filled by someone on the 2013-14 roster, and that’s before the Kyrie Irving and Kevin Love injuries led to newcomers James, Timofey Mozgov, J.R. Smith and Iman Shumpert logging large workloads in the playoffs.

The league’s shining example of roster stability for years has been the San Antonio Spurs. It’s not without validity, either: San Antonio has had a roster continuity percentage lower than 75 percent in just three seasons since 1998-99. The Miami Heat, on the other hand, has had a roster continuity percentage higher than 70 percent just five times since 2000-01.

While making moves in the offseason is certainly necessary, particularly now that there’s a salary cap situation that wasn’t evident four decades ago, teams should consider keeping a team’s nucleus intact. San Antonio and the Memphis Grizzlies have continued to trot out eerily similar lineups the past five years and, unsurprisingly, both are perennially in the playoffs. Each roster and situation is different, but unless a franchise is operating with a duct-taped roster, there’s merit in keeping a team together.

Josh Planos has been published at the Wall Street Journal, the Atlantic, the Guardian, the Pacific Standard and VICE, among other publications. He has been heard on CBS Sports Radio, Fox Sports Radio and ESPN Radio. Planos is currently a Digital Editor at KETV NewsWatch 7 and a freelance writer.