With three NBA championships over the past four seasons, the Golden State Warriors are a bona fide dynasty. Regardless of how you feel about its 2016 acquisition of Kevin Durant, which lifted an already historic team to an entirely new level of dominance, Golden State has done something special: Only seven NBA teams have ever pulled off the three-rings-in-four-years trick. Even for the most talented roster ever, that’s not an easy thing to accomplish.

The league’s history is, in many ways, defined by its dynasties in a manner that other sports aren’t, and the Warriors are nothing if not the defining team of our current era. But where do they rank in comparison with those other dynastic teams from years past? Although there’s no definitively correct answer, it’s still fun to argue. So we thought we’d fact-check Golden State’s case using our Elo ratings, which are designed to measure a team’s inherent strength at any given moment.

Let’s start with the best runs of four consecutive seasons according to the method we favor for judging historical Elo seasons: a blend of a team’s final, peak and full-season-average ratings. To ensure that a team rated highly every year, I took the harmonic mean of its blended rating from each of the four seasons. Here are the all-time rankings, excluding any duplicates from the same franchise over the same span of years:

Elo’s best four-year runs Highest average* blended Elo across four consecutive seasons for NBA franchises, 1948-18 Team Seasons Titles 4-Year Blended Elo Golden State Warriors 2015-18 3 1789 Chicago Bulls 1995-98 3 1745 San Antonio Spurs 2013-16 1 1736 San Antonio Spurs 2003-06 2 1719 Chicago Bulls 1991-94 3 1717 Boston Celtics 1984-87 2 1716 Los Angeles Lakers 1985-88 3 1715 Los Angeles Lakers 2008-11 2 1706 Los Angeles Lakers 2000-03 3 1703 Miami Heat 2011-14 2 1702 Utah Jazz 1995-98 0 1702 Milwaukee Bucks 1971-74 1 1701 Philadelphia 76ers 1980-83 1 1698 Detroit Pistons 1987-90 2 1695 Oklahoma City Thunder 2011-14 0 1692 * Using the harmonic mean. Source: Basketball-Reference.com

According to Elo, the Warriors of the past few years have snapped off what is easily the best stretch of four consecutive seasons any NBA team has ever had. By that standard, then, they absolutely belong in the conversation of the league’s greatest dynasties. But of course, they’ve also only had four dynasty-level seasons to speak of. As hard as it is to remember what things were like before the Warriors started dominating, Golden State’s reign has been brief in dynasty terms.

So how should we measure the Warriors’ four-year stretch against, say, the Chicago Bulls’ pair of three-peats in the 1990s or the Boston Celtics’ ridiculous championship monopoly of the 1960s?

To help put various dynastic runs on equal footing, I began with a thought experiment: How easily would a generic championship-caliber team be able to match a given multiyear run from NBA history? The most difficult-to-replicate stretches are, by definition, the most impressive ones — and in my conception, make for the best dynasties — because a normal contending team is so unlikely to pull them off.

As a way of quantifying this, I assigned our generic team a preseason Elo rating of 1600, aka the average preseason Elo for NBA champs since 1948. I then ran a series of regressions to determine what we’d expect its average blended Elo over the next given stretch of seasons to be and compared every possible stretch of seasons in each franchise’s history to those expected ratings. I isolated things down to NBA teams that won at least three championships in a span of 10 or fewer years and tossed out overlapping runs from the same franchise that didn’t prove to be more impressive than other, higher-ranking ones. The dynastic runs we’re left with are the most successful — i.e., the most difficult to replicate — out of all possible multiyear periods in NBA history.

As you can see in the table below, the most impressive period for one team might last only three years, while another’s could span an entire decade. For example, the current Warriors’ best period came over the 2015 to 2018 period, because their four-year mark of 1789 was 188 points higher than what we’d expect our generic contender’s average blended Elo over the next four seasons to be. Another example: The San Antonio Spurs’ best run came over 10 seasons, from 1998-99 to 2007-08, during which time they had a blended Elo rating of 1702 — 145 points better than we’d expect that generic championship-caliber team to do over a 10-season period. Some franchises, like the Bulls, are listed twice in rapid succession, because they had multiple short runs that were highly impressive and didn’t overlap.

Here’s Elo’s ranking of all-time NBA dynasties:

The Warriors are Elo’s most impressive NBA dynasty Highest multiyear blended Elo rating relative to expectation for a championship-caliber team for NBA franchises that won at least three titles in a span of 10 or fewer years, 1948-2018 Team Seasons Championships Blended Elo vs. Exp. Golden State Warriors 2015-18 3 of 4 1789 +188 Chicago Bulls 1996-98 3 of 3 1793 +181 San Antonio Spurs 1999-08 4 of 10 1702 +145 Chicago Bulls 1991-93 3 of 3 1746 +134 Boston Celtics 1980-87 3 of 8 1696 +130 Los Angeles Lakers 1982-91 4 of 10 1685 +128 Boston Celtics 1959-67 8 of 9 1676 +115 Los Angeles Lakers 1998-04 3 of 7 1684 +112 Minneapolis Lakers 1949-54 5 of 6 1651 +72 Miami Heat 2005-14 3 of 10 1596 +39 A “championship-caliber” team starts out with an Elo of 1600, and dynasties are measured against what we’d project that team’s multiyear blended Elo to be after a given number of years. For franchises that made the list multiple times in a given time period, only their highest-rated stretch during the span was included. Source: Basketball-Reference.com

Even compared with other dynasties, the current Warriors and Michael Jordan’s second Bulls three-peat stand out. Our method says that it is slightly more difficult for a typical championship contender to replicate Golden State’s four-year run than Chicago’s three-year stretch, but that’s just splitting hairs. Either dynasty could be considered the GOAT, which is truly a testament to the impressiveness of what the Warriors are currently doing.

A few notes on the rest of the list: The Spurs dynasty is difficult to pin down — we once coined the term “Grover Cleveland” (instead of the often overused D-word) for teams like San Antonio that won multiple championships but never consecutively — but this approach considers their most difficult-to-duplicate period to be that aforementioned decade from 1999 to 2008. It also considers the Shaq-and-Kobe Lakers’ best run to be the seven seasons from 1997-98 to 2003-04, which includes (but is not limited to) the 1999-2000 through 2001-02 three-peat that most fans consider to be their dynastic peak.

The Russell-era Celtics strike me as surprisingly low on the list, perhaps as a consequence of only examining 10-year windows of time at a maximum (the Celtics won 11 rings in 13 seasons, from 1957 to 1969). But Elo also has never been all that high on those Boston teams, with only one — the 1965 version — even cracking the top 50 for single seasons. In some ways, those Celtics were a very early prototype for today’s superteams who pace themselves through the regular season and then peak during the playoffs: Boston won 60-plus games in only two of their 11 championship seasons during that span and won a pair of titles with fewer than 50 regular-season wins. However conducive that was to winning championships, it didn’t help earn the Celtics many Elo brownie points.

Finally, Dwyane Wade’s Miami Heat also qualify for this list, although they’re not necessarily a “dynasty” that many people think of when perusing the annals of NBA history. Between Wade’s Finals MVP turn in 2006 and the two rings they tacked on after LeBron James and Chris Bosh joined the team in 2010 — plus a number of solid seasons in between — the Heat could be considered a dynasty if you squint hard enough. If so, however, it also makes sense for them to be stashed away at the very bottom of the rankings here.

But back to the Warriors. Elo already considers them to be on par with the greatest dynasties the game has ever seen, and as my colleague Chris Herring wrote over the weekend, they also seem poised to keep their core together longer than most. Although the end does come sooner for these types of teams than we tend to think while we’re in the middle of their dominance, Golden State now has a chance to build on what it’s already accomplished and solidify itself as the clear No. 1 choice among the NBA’s all-time dynasties. Let’s see if they can take advantage of the opportunity.