Serious Sports Journalism
BY Kevin Litman-Navarro
The San Antonio Spurs are a model organization, a franchise characterized by class and sustained success. Absent recent drama and the sting of long awaited goodbyes, Spurs fans have every reason to be happy. This is known.
The New York Knicks are ... different. After infamously gutting their entire roster to trade for Carmelo Anthony in 2011, New York City's beleagured franchise has hobbled through years of mediocrity. Since that trade — going back to 2005, in fact — the Knicks have only won one playoff series in three appearances. Knicks fans are sad. This is also known.
To most basketball fans, the Spurs' and Knicks' divergent fates are no surprise. According to conventional wisom, team success is tied to roster continuity. The Spurs have it, and the Knicks don't.
Perhaps growing up in New York is what gave rise to Jerry Seinfield's take on sports. If you're a Knicks fan, you really are rooting for clothes.
The Laundry Fanbases
Look, I get no joy from pointing out the fungible nature of a Knick's roster. I'm a Laker fan, and the longest-tenured player on my team is a third-string center entering his third year. I get it. It's not fun. At some point, you are cheering for an abstraction, the idea of a team more than the reality of one.
Unforunately, the data don't lie, and a look at roster continuity over the years confirms the eye test results. Even more bad news for the laundry fanbases: while it's not massive, there is a clear relationship between roster continuity and team success.
The chart below shows a team's average wins and average roster continuity (percentage of minutes used up by a player who used those minutes in the previous season). Without looking, can you guess who is at the top, and who is at the bottom?
Average Wins and Roster Continuity Percentage since 2005
SOURCE: Basketball Reference
The Value of Consistency: One-Third of a Win
If we look at the relationship between roster continuity and wins, we can actually put a number on the importance of keeping a team together. Taking into account every single year going back to the inaugural NBA season, this magic number is .344.
That is, every 1% of roster continuity is correlated with an additional one-third of a win.
Scroll around the scatterplot to see which organizations were most successful while staying true to the team ethos.
How Roster Continuity Correlates With Wins In Every NBA Season
SOURCE: Basketball Reference
How To Win Friends and NBA Championships
If there's a team that has perfected the practice of team growth, it's the modern Golden State Warriors. Before pulling of the basketball heist of the century, the Warriors had achieved consistent improvement in roster continuity that was directly tied to an increase in wins, culminating in the 73-win 2015-2016 season.
It's a pretty simple solution: get a few great players, and let them figure it out.
Golden State Warriors Wins and Roster Continuity Percentage
Kevin Durant joins the team.
100
The Warriors win first of
three championships.
80
60
40
20
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017