The Boston Celtics and the hazards of youth and roster turnover

Before the season has even started there are two storylines surrounding the 2017-18 Boston Celtics:

• They are really young.
• They are returning only four players from last year’s team.

Not exactly breaking any news there, right? But the question to be asked is: Does it matter?

The NBA is as full of old adages as it is with superstar divas. But two cliches that apply here are:

• Young teams don’t win.
• Roster continuity matters.

Are either of those statements true? Can a very young team win at a high level and compete for a title? What about a team that turned over a large chunk of its roster?

As it pertains to the Celtics, you can’t really argue that either of these points is true. The Celtics are young, and they turned over a lot of the roster. But does either portend certain doom?

To compare a 15-man roster to another 15-man roster (or 17 to 17 if you want to count the guys on two-way contracts) is kind of an exercise in futility. Rarely do NBA teams play all 15 players. That only happens with teams who are rebuilding (or tanking!) or teams who face a rash of injuries. Therefore, it makes more sense to run a comparison based off a rotation of 10 players, as most NBA rotations settle around 10 players. Even Brad Stevens, whose detractors grouse about him playing 11 to 12 players, sees a discernible drop in minutes played over the course of the year from player 10 to player 11.

For this exercise, to try and understand just how much relying on youth matters, and how impactful a lack of continuity is, we went back and compared the last ten years of data for each of the NBA’s final four teams for a given season. Given that a conference finalist berth generally allows a team to enter the “title contender” conversation, it seemed fair to draw the line at the final four teams.

There are also a couple of Boston-related reasons for using 10 years and the label of contender. The first is that this group is regularly compared to the last Celtics team to raise a banner: the beloved 2007-08 team. The reason for the comps are the large roster turnover and the addition of two superstars over the summer.

The second reason to cut it off at contenders is that this version of the Boston Celtics is supposed to be just that: a contender. Whether or not you believe they can upend LeBron James and the Cleveland Cavaliers in the East before taking on the mighty Golden State Warriors in the Finals is sort of irrelevant. If you don’t believe it, nothing you read here is likely to change your mind. To be honest, if you do believe it, the same probably holds true. But consider it another data point as you prep for what we all hope will be a long season with an extended playoff run.

Here are the 10 players who project to log the most minutes played this coming season for the Celtics. Also included are their years of experience and if they were with the club last season.

*Expected to be one of Semi Ojeleye, Guerschon Yabusele and Daniel Theis

On the youth front, only Al Horford has logged double digits in terms of NBA years of experience, and Horford’s only just there at ten years. Next closest is Gordon Hayward with seven years. Kyrie Irving and Marcus Morris check in with six years of experience apiece. The average years of experience for the full 10-man group is four years. The Celtics also project to rely on two rookies in the 10-man rotation. Both of these numbers are key, as we examine the last 40 teams to make it at least as far as the Conference Finals.

In the last 10 years, only one team has reached a Conference Finals that was younger than this year’s Boston Celtics: the 2010-11 Oklahoma City Thunder. That year the Thunder checked in with an average of just three years of experience. That group fell to the eventual champion Dallas Mavericks in five games. A year later, the Thunder made it to the NBA Finals.

Only one other team checks in even as young as Boston projects to be this year: the 2012-13 Indiana Pacers. That Pacers group matches Boston with an average of four years of experience. Only two other teams had less than five years of average experience: the aforementioned 2011-12 Thunder and, oddly enough, last year’s Boston Celtics.

For reference, the average years of experience for the 40 conference finalists in our dataset was 6.5 years. Examining just the 20 NBA Finals teams, it jumps to 7.2 years. And looking at just the teams that eventually hoisted the Larry O’Brien Trophy, it nudges up to 7.5 years.

So, what can we glean from this? It seems like old adage number one (“Young teams don’t win.”) is probably true. Most of the last 40 teams to make a Conference Finals contained players in the middle of their careers. The only truly “old” team in the set was the 2010-11 Dallas Mavericks, who averaged 10 years of experience. Those Mavs boasted six players with 10 or more years, topped by Jason Kidd’s 16. The youngest player in the rotation that year for the Mavs was J.J. Barea, who had four years of experience at the time.

What about rookies? We mentioned that the Celtics are likely to have two rookies in the top 10 in minutes played for this year. Only one team of the 40 studied relied on two rookies in their rotation: the 2007-08 Detroit Pistons, who had rookies Rodney Stuckey and Arron Afflalo. As we all know, that team fell to the Celtics, en route to Boston capturing banner 17.

As a matter of fact, only 12 teams out of 40 made the Conference Finals with a rookie in the top 10 of their team’s minutes played. When you look at just the NBA Finals, that number gets halved to just 6 teams relying on a rookie for minutes. For what it’s worth, only one rookie in the last 10 years has had a prominent role (defined here as within the top 5 in minutes played for his team) on a conference finalist: Kawhi Leonard for the 2011-2012 San Antonio Spurs.

So, just like with young rotations, relying on rookies doesn’t seem likely to produce a contender—not that it hasn’t happened, but it hasn’t happened on any sort of regular basis.

Alright, so we know the Celtics are facing an uphill battle because of how young they project to be, but what about roster continuity? As covered above, Boston returns just four players from their top 10 in minutes played last year. As a matter of fact, the Celtics return just four players from last year’s roster in total. But that shouldn’t matter as much as the youth thing, because other teams have similarly blown up the roster and went on to success. Well…as Lee Corso likes to say “Not so fast my friend!”

The average roster turnover from year to year of the last 40 conference finalists is 2.6 players. The difference between NBA Finals squads and champions is fairly negligible, at 2.4 and 2.3 players turned over. Even the beloved 2008 Celtics, who we generally remember as having blown up the roster, only turned over five players from the previous year who were in the top 10 in minutes played.

The teams with the most turnover? The 2010-11 Chicago Bulls, who lost to the Miami Heat and the 2014-15 Cleveland Cavaliers, who lost in the Finals to the Warriors. Both of those teams match Boston’s turnover this year of six players.

Let’s sum it up then. Youth doesn’t win. Relying on rookies doesn’t work. And turning over most of the roster isn’t usually a path to success. But none are a death knell either. A handful of teams in the dataset have overcome youth or have built chemistry quickly enough to disregard the roster turnover. The one scary thing for the Celtics? No team has done both in the last 10 years.

The only thing more fun than winning a championship is making history while doing it. Sports are full of achievements that have never been done before. Maybe this year’s Celtics break the trend and make it to at least the Eastern Conference Finals as a young, new group.

If we’re going to compare this year’s Celtics to the last champion group from 2008, let us also remember what Kevin Garnett taught us after the final buzzer sounded in Game 6 and he was finally a champion:

Enjoy the season everyone!