The Knicks and Lakers are putting all of their hopes of building a superteam on their transactions this offseason. But an analysis of NBA champions shows that when it comes to finding title-winning talent, there’s no place like home.

The Knicks’ dream of drafting Zion Williamson has dissolved and vanished with the unfortunate bounces of a few ping-pong balls, but a dream offseason is still possible for the moribund Madison Square Garden occupant. The Knicks could still sign Kevin Durant and an All-NBA guard—either Kyrie Irving or Kemba Walker—in free agency. Even with two max players on board, they could trade their no. 3 pick, a collection of recent draftees, and future picks for Anthony Davis. Assembling a superteam through transactions may not carry the same sense of organic excitement as drafting the next great NBA prospect, but a Knicks team led by that trio would vault to the upper echelon of the Eastern Conference.

But that evolved dream relies on a heightened sense of New York City exceptionalism, with the Knicks purportedly posing as a prime destination because of market alone, and not a lot of precedent. As Sean Fennessey noted in a recent Ringer Slack discussion, excepting the 2004 Pistons, “I can’t think of an NBA champion in which at least one of the team’s two best players wasn’t homegrown/drafted. A Knicks title driven by free agents would be highly anomalous.”

We can quantify just how anomalous it would be by examining past title-winning rosters. For these purposes, a player counts as “homegrown” for a team if he spent his first season with that franchise. More specifically, that notion can manifest in four ways:

First, the most direct path: A player was drafted by the team in question and played for it. This is the most common method, seen with Steph Curry on the Warriors, Tim Duncan on the Spurs, Magic Johnson on the Lakers, and more.

Second, a player was drafted by a different franchise and traded to the team in question before playing a game. That means Dirk Nowitzki counts as a homegrown Maverick, Kobe Bryant as a homegrown Laker, and so on.

Third, a player signed with the team in question as an undrafted free agent. This method accounts, for instance, for Udonis Haslem as a homegrown member of the Heat.

And fourth, a player who fulfilled one of the other three conditions left the team in question and then returned. Even though James spent four years in Miami, nobody would dispute that he should count as a homegrown Cavalier for the purposes of the team’s 2016 title run.

Those logistical considerations squared, let’s dive into the results for every champion since 1979-80. (That was the first season with a 3-point line, as well as the debuts for Johnson and Larry Bird, so it seems a fitting starting point for the “modern” NBA.) Here’s the full list of each title-winning team’s top two players, using the all-encompassing statistic win shares, filtered into Homegrown and Not Homegrown categories. The “Total Homegrown Ratio” column shows the percentage of each team’s regular-season win shares that came from homegrown players. (Players with negative win shares were removed from this analysis.)

Top Two Players on Title-Winning Teams

Team Homegrown Not Homegrown Total Homegrown Ratio Team Homegrown Not Homegrown Total Homegrown Ratio 1979-80 LAL Magic Johnson Kareem Abdul-Jabbar 41% 1981 BOS Cedric Maxwell Robert Parish 51% 1982 LAL Magic Johnson Kareem Abdul-Jabbar 51% 1983 PHI Moses Malone, Julius Erving 43% 1984 BOS Larry Bird, Kevin McHale Robert Parish 66% 1985 LAL Magic Johnson Kareem Abdul-Jabbar 67% 1986 BOS Larry Bird, Kevin McHale 55% 1987 LAL Magic Johnson, James Worthy 83% 1988 LAL Magic Johnson, Byron Scott 79% 1989 DET Dennis Rodman Bill Laimbeer 46% 1990 DET Dennis Rodman Bill Laimbeer 54% 1991 CHI Michael Jordan, Scottie Pippen 78% 1992 CHI Michael Jordan, Horace Grant 83% 1993 CHI Michael Jordan, Horace Grant 87% 1994 HOU Hakeem Olajuwon Otis Thorpe 48% 1995 HOU Hakeem Olajuwon Kenny Smith 47% 1996 CHI Michael Jordan, Scottie Pippen 59% 1997 CHI Michael Jordan, Scottie Pippen 59% 1998 CHI Michael Jordan Dennis Rodman 51% 1999 SAS Tim Duncan, David Robinson 53% 2000 LAL Kobe Bryant Shaquille O'Neal 32% 2001 LAL Kobe Bryant Shaquille O'Neal 32% 2002 LAL Kobe Bryant Shaquille O'Neal 44% 2003 SAS Tim Duncan, Tony Parker 60% 2004 DET Chauncey Billups, Ben Wallace 25% 2005 SAS Tim Duncan, Manu Ginobili 60% 2006 MIA Dwyane Wade, Udonis Haslem 42% 2007 SAS Tim Duncan, Manu Ginobili 60% 2008 BOS Paul Pierce Kevin Garnett 50% 2009 LAL Kobe Bryant Pau Gasol 51% 2010 LAL Kobe Bryant Pau Gasol 48% 2011 DAL Dirk Nowitzki Tyson Chandler 28% 2012 MIA Dwyane Wade LeBron James 40% 2013 MIA Dwyane Wade LeBron James 31% 2014 SAS Kawhi Leonard, Tim Duncan 58% 2015 GSW Stephen Curry, Klay Thompson 63% 2016 CLE LeBron James, Tristan Thompson 55% 2017 GSW Stephen Curry Kevin Durant 47% 2018 GSW Stephen Curry Kevin Durant 47%

We see first that Sean was right: Besides the 2004 Pistons, who signed Chauncey Billups as a free agent and traded for Ben Wallace, you’d have to go back more than 35 years to find the last championship team without a homegrown player among its top two. That was the 1983 76ers, who signed Julius Erving out of the ABA and traded for Moses Malone.

Overall, the average champion since 1980 has received a healthy 53 percent of its win shares from such roster spots. Don’t like win shares? The same general concept applies when looking just at box score stats: The average champion since 1980 has also received 53 percent of its total points from homegrown players, 49 percent of its rebounds, and 56 percent of its assists.

That trend also proves true for the teams that lose the Finals, too. Since 1980, 35 of 39 Finals runners-ups had at least one homegrown player in their top two, and the exceptions still had a homegrown star who helped define the team’s identity, even if he ranked just outside the top two in win shares:

Dwyane Wade for the 2013-14 Heat (LeBron James and Chris Bosh ranked 1-2 in win shares)

Patrick Ewing for the 1998-99 Knicks (Larry Johnson and Marcus Camby ranked 1-2)

Isiah Thomas for the 1987-88 Pistons (Adrian Dantley and Bill Laimbeer ranked 1-2)

Maurice Cheeks for the 1979-80 76ers (Julius Erving and Bobby Jones ranked 1-2)

And even as player movement has become a larger story in the league over the decades—unrestricted free agency wasn’t instituted until 1988—championship teams have generally maintained a reasonable homegrown balance. Although winners in the 2000s and 2010s aren’t quite as insular as their predecessors, they still approach a 50-50 split—and, most importantly, they still almost always have at least one leading star who was homegrown.

Championship Teams’ Homegrown Ratio

Decade Average Homegrown Ratio Decade Average Homegrown Ratio 1980s 58% 1990s 62% 2000s 46% 2010s 46%

The league’s most recent titleists are no exception. Despite Durant’s addition, the current Warriors dynasty formed with an extremely homegrown core. The team drafted Curry in 2009, Klay Thompson in 2011, and both Harrison Barnes and Draymond Green in 2012. The homegrown percentage for the 2015 Warriors, in fact, was the highest for any championship team since 1991–1993, when Michael Jordan and Scottie Pippen led a group of homegrown Bulls to a three-peat.

Even the 2016 Cavaliers, who seemed put together in a piecewise fashion, supported a strong homegrown faction with Kyrie Irving, Tristan Thompson, and Matthew Dellavedova joining James in his return to Cleveland. And this year, either the largely homegrown Warriors will win again, or the Raptors—who have Pascal Siakam, a 2016 first-round draft pick for Toronto, as their no. 2 option, among others—will continue the trend.

Of course, another way to say that teams need homegrown players to win is that teams need top-level talent to win, and the brightest stars required to win a title don’t often change teams. The homegrown players who led their team to a title were often high lottery selections: Johnson, Worthy, Olajuwon, Robinson, Duncan, and James were all no. 1 overall picks, while a host of others went in the top five.

It sounds silly, then, to suggest that the Lakers couldn’t win with LeBron and Anthony Davis, or that the Knicks couldn’t win with Irving, Davis, and Durant—two former no. 1 picks and a no. 2. It’s more that such a path is nearly unprecedented. Previous superteams have had at least one superstar already in place, whether with Paul Pierce in Boston or Curry and friends in Golden State. The Lakers and Knicks, especially if they trade all their promising young players for Davis, wouldn’t have any of that foundation.

On average, of a championship team’s five best players, 2.8 have been homegrown. Of a champion’s next five players (ranked 6-10 in win shares), just 1.7 have been homegrown, with the majority recruited from other teams in free agency or trade. In other words, the typical path to build a title-winning roster has been to construct the core with homegrown talent and use transactions for depth. A free-agent bonanza for a coastal power this summer would essentially seek to invert that formula.

Will it work? Maybe. The NBA has the least parity of any major American sports league; notice how often the same names repeat in the first chart up above. Most team-building circumstances don’t lead anywhere near title contention, so there’s no reason not to try this one. But there should be no real expectation that a team without a homegrown leader would succeed—if the Knicks or Lakers even manage to land the superstars of their dreams in the first place.