Anyone who’s watched the Boston Celtics since October has been aware of their championship capabilities. At least, you would hope that’s the case.

With Friday’s win, though, Boston stamped its name into the unofficial title contention club. Recording their 40th win of the year, they became the first team this season to satisfy Phil Jackson’s 40-before-20 criteria.

Jackson, arguably the greatest coaching figure in the history of basketball, is a decorated legend with 13 combined championships as coach and player. In 2008, when his Lakers were in the midst of a revival powered by the Kobe Bryant and Pau Gasol connection, Jackson stated his theory.

“You must win 40 games before you lose 20 to be seen as an elite team,” Jackson said.

Simple enough, right? Claiming that teams should be playing at a 56-win pace to be considered a legitimate championship contender is hardly groundbreaking news.

But it’s a helpful exercise — with a successful track record — that can weed out the pretenders and provide an accurate snapshot of which teams could hold the Larry O’Brien Trophy in June.

The reasons behind the rule make sense, especially when you dig into what a ‘40 before 20’ unit means. Not only does it require superstar talent at the top, but there’s a mixture of health, roster balance, and fourth quarter composure that needs to be met.

Above all else, health and good fortune have to be in your favor. Rarely will a team be heavily affected by injuries and still be on track for 56-plus wins. Lineup continuity matters in the NBA, as everyone was just reminded in the 2023 NBA Finals when Denver’s patience finally paid off. In Jamal Murray’s return season, the Nuggets developed winning habits all year, avoided nagging injuries to their core rotation, and improved on the margins by having veteran role players fill the gaps they were missing.

It also requires solid balance, meaning you won’t see teams dragging a terrible defense to a championship-level record. Unless, of course, we’re talking about LeBron James and the 2018 Cavaliers that had to rework 80% of their rotation at the trade deadline. Even then, they weren’t competing with the Warriors. The Finals were simply a formality that year.

Taking a look at this year’s 40-before-20 candidates, the lowest offensive or defensive rank belongs to the Cavaliers and Timberwolves. They sit 16th and 17th, respectively, in points scored per 100 possessions. Three contenders (Celtics, Clippers, and Thunder) are firmly in the top 10 of both, and the Nuggets are 12th defensively with a good shot of reaching 10th if they put together another strong week.

While it can seem like a “duh” statement that Boston and other top seeds are firmly in the title mix, it’s better to contextualize the reverse effect: Failing to reach this benchmark is almost certainly a death sentence for a team’s championship hopes.

Since the 3-point line was installed during the 1979-80 season, 40 of the last 44 champions have met the 40-before-20 criteria. As you can see in the table below, the only squads to miss the mark were the 2021 Bucks, 2006 Heat, 2004 Pistons, and 1995 Rockets.

That’s a 90.9% success rate for Jackson’s theory. Plus, all 11 of Jackson’s title-winning groups accomplished it:

Much like any rule, however, there are exceptions.

Because of the unusual circumstances surrounding the 2021 season, I’m tempted to throw that year aside. At the very least, it deserves an asterisk. It was the first season directly after the bubble and Covid shutdown. Players had the shortest offseason in NBA history, which lasted from the day after the Finals on October 12 to the official start of training camp on December 1. Preseason games started 10 days later. Additionally, there were many instances of games being postponed due to Covid outbreaks.

The 2021 Bucks missed the mark by four losses, but still found a way to win the East and capture their first title in 50 years. In order to achieve that, Milwaukee had to overcome two separate 2-0 deficits in the playoffs. They became the second team in history to do so … after the 2021 Clippers managed it three weeks earlier. It was simply a weird time in the NBA and I don’t think people have fully grasped how unique that time was. Some arenas weren’t even allowed to fill their stands until midway through the postseason.

Looking at the 2004 Pistons and 2006 Heat, it’s safe to say the NBA is a completely different experience than it was two decades ago. Detroit rode one of the greatest defenses in league history to a championship at a time when teams weren’t shooting many threes and offenses were operating in a phone booth, so to speak. The concept of spacing didn’t exist. Then, two years later, Miami won four straight series despite ranking 11th out of 16 playoff teams in offensive efficiency. It took an hellacious defensive stretch and one of the highest free throw rates in modern history from Dwyane Wade for the Heat to overcome a 2-0 deficit.

In the past, you could raise a banner with an unbalanced team. The adage of “defense wins championships” was very much a real thing from 2003 to 2008.

That’s just no longer the case. The Pistons and Heat will be viewed as the clear exceptions to the rule in a non-shortened season.

As of now, the near-misses to this year’s 40-before-20 class appear to be the Milwaukee Bucks (34-19) and New York Knicks (33-19). Both teams are still technically alive, but the odds aren’t in their favor.

Milwaukee recently made a coaching change despite having an impressive record, but hasn’t played enough competent defense to be considered a top-tier threat. The Knicks have recently soared up the standings by winning 16 of their last 20 games and making huge splashes with trades.

Out West, the Phoenix Suns (31-21) will be the strongest team to challenge Jackson’s theory. They were littered with injuries to begin the season and have played at a 60-win pace since Bradley Beal returned to the lineup:

The data suggests Phoenix should be considered in the same class as the Clippers, but it’s understandable why they aren’t. Typically, if injuries affect a team’s first two months of the season, chances are they will creep up again.

With almost two-thirds of the season played, Boston has a five-game lead in first place for the Eastern Conference’s top seed. They are the only team on pace for a 60-plus win campaign and have a legitimate shot to enter the “50 before 20” club.

Every piece of criteria needed to be considered the “favorite,” Boston has crossed it off.

Filtering out garbage time, the Celtics are third in offensive rating (121.4) and third in defensive rating (112.1). Outscoring opponents by 9.3 points per 100 possessions, they are steps ahead of last year’s team that came one game from reaching another NBA Finals. Perhaps if Miami’s Caleb Martin didn’t transform into Klay Thompson during the playoffs, we would’ve seen a Boston-Denver showdown that had a bit more intrigue.

Offensively, their approach is ideal for today’s game. Boston generates 43.7% of their overall shots from 3-point range, the highest figure in the league. They save most of their long twos for late-clock situations.

As of this writing, 28 of their 42.8 long-range shots per game are catch-and-shoot opportunities. That’s 65.5% and a healthy amount for a championship-caliber offense.

They are on pace to drill 1,325 threes for the season, which would rank second all-time behind only the 2022 Warriors that had an embarrassment of riches on the perimeter with Stephen Curry, Klay Thompson, and Jordan Poole bombing away from deep.

The Celtics also refrain from turning it over at an alarming rate, which can often hold back an offense from reaching its full potential. They are only giving it up on 12.6% of their total possessions, a top five mark and slight improvement from last year.

You can add in the fact they don’t get themselves in foul trouble. Boston currently holds the lowest opponent free throw rate in the league. That might be the most remarkable feat of their season when you consider how aggressive Derrick White and Jrue Holiday play at the point of attack and how often opponents are trying to attack the paint. The appropriate credit must be given to Kristaps Porzingis, who has easily been one of the five best rim protectors in basketball during his first year in Boston.

On the health front, their starters have logged plenty of time together. It’s the number one reason they have already crossed the 40-win checkpoint. As of Friday’s win, the lineup featuring Holiday, White, Brown, Tatum, and Porzingis has played 884 total possessions, the eighth-most of any lineup in basketball. During those minutes, Boston has a +12.2 net rating.

Boston also just fortified its bench when President of Basketball Operations Brad Stevens acquired Xavier Tillman Sr. from the Memphis Grizzlies. Tillman’s offensive production has looked rough this year, as he’s 14.3 percentage points below league-average true shooting after being four points above it last season. But he’s never played in a well-spaced system like Joe Mazzulla’s, where he will undoubtedly get more short-roll opportunities after ball-handlers get blitzed.

Defensively is where Tillman’s impact will be felt, though. He’s a 6’8” brute capable of switching onto the perimeter and guarding bigger wings in isolation, if needed. Positional versatility is one of the most desired skills in the modern league and Tillman checks that box. In Memphis, he spent 61% of his minutes at center and 39% at the four this season. While he’s not going to play a ton of minutes in the postseason when Boston prioritizes five-out spacing with Porzingis and Horford, it’s an acquisition that gives them adequate insurance and prepares them for different matchups where his physicality might be required.

The Celtics haven’t been nearly as dominant lately, with just a +5.8 net rating since January 18th, but Mazzulla isn’t concerned about margin of victory. Over the last couple weeks, he’s tried to stress how competitive the modern league is and why it’s okay if every game doesn’t finish in a blowout fashion. He’s even called it an “arrogant” mindset to believe the Celtics should decimate opponents every night – and he’s not wrong.

Dominant stretches will come and go for elite teams during the season. There’s a reason we’ve only seen a handful of teams finish the year with a double-digit point differential.

The latest example of Boston looking shaky was Friday against Washington when they allowed 71 first-half points and trailed by seven at the break. But the Celtics quickly responded by locking down in the third quarter and holding the Wizards to just 16 points on 28 possessions.

Mazzulla was far more focused on how his team countered the initial punch.

“I do think there’s been moments of slippage throughout games,” he said. “Which, obviously is going to happen throughout (the season). But I think what I care more about is our approach to those slippages. I don’t think you’re going to eliminate those. It’s just not going to happen. But the response to those is important. Making sure they don’t slip for multiple quarters, or multiple games.”

After the sour ending last May in the East Finals, the Celtics know they can’t make up for those mistakes in February. They are in the dog days of a long season with a comfortable cushion at the top.

With their current rotation, they have the necessary tools to meet the “championship or bust” expectation that naturally gets attached to a group this talented. All they can do right now is take care of business and secure homecourt. Barring a collapse, that appears to be coming in the near future.