Reason 1: Lackluster Local-Market TV Revenue
No, really. I'm serious.
Start with the salary cap, because everything runs through it. The cap is tied to something called Basketball Related Income, or BRI. That's the pool of every dollar the league takes in: ticket sales, merchandise, TV deals, all of it. The logic is simple. When BRI goes up, the cap goes up and players get paid more.
Now picture BRI as a pie. Roughly a 10% slice of that pie comes from local media deals, and that slice is becoming quite stale.
Here's what a local media deal actually is. Your team's non-national games get broadcast on a Regional Sports Network, or RSN. The team sells the RSN the rights to air its games, and the RSN pays for them. That payment is part of BRI. The problem is that the same cord-cutting that blew up your cable bundle is now gutting the RSNs, and their whole business model is collapsing.
The company behind FanDuel Sports Network was unable to make their monthly rights payments to NBA teams last season, then shut down entirely, leaving franchises scrambling to figure out how they'll even broadcast next year. MSG Networks, buried in debt, cut what it pays the Knicks by 28% for the season that just ended. Spectrum has been trying to offload SportsNet, which holds the Lakers' rights. NBC Sports' regional networks look next in line to be sold off. The short version: if it's a regional sports network not owned outright by the team, it's a disaster right now.
But local media is only the small slice. The biggest piece of the BRI pie by far is national media rights, the league-wide deals with the major networks. And to understand why everyone thought they would be living high on the hog this time around, you have to go back to the last time it exploded.
In 2014, the NBA signed a deal with Disney and Turner that roughly tripled its previous national TV revenue. Back then there was no rule to ease that money in gradually, so the full jump hit the cap at once and it spiked 32% between 2015-16 and 2016-17. That single leap is how the Warriors were able to sign Kevin Durant. It's also how these contracts happened:
Chandler Parsons, 4 years, $94M
Evan Fournier, 5 years, $85M
Bismack Biyombo, 4 years, $72M
Timofey Mozgov, 5 years, $64M
Ian Mahinmi, 4 years, $64M
Meyers Leonard, 4 years, $41M
That was a one-time flood of national TV cash into BRI, and the cap didn't keep climbing 32% a year afterward. It leapt once, then flattened out. So players who happened to hit free agency even one summer later missed the large payday. It was a mess, and both sides knew it.
So in the next labor deal, the players and owners agreed to something called cap smoothing. The idea is exactly what it sounds like. Instead of letting a giant revenue jump crash into the cap all at once, you spread it out, capping how much the cap can rise in any single year. No more one-summer gold rush, no more players left behind because of when their contract happened to expire.
Fast forward to 2024. The league signs another national TV deal, another near-tripling of revenue. But this time smoothing is in place, so the cap can't spike 32% like it did in the summer of 2016. With the increase maxed out at 10%, everyone assumed those healthy raises would roll in year after year after year.
Then reality showed up. The 2026-27 cap came in at just 6.67%, well short of what teams had penciled in. The league projects the following year, 2027-28, at only a 5.5% rise. Assume the two seasons after that also land near 5.5%, and $35M in cap room disappears by the 2029-30 season, vanishing right alongside the RSNs.
Why does this matter?
To answer that, you first have to understand how player contracts work. Let's use the max contract as our example.
Max contracts come in different sizes depending on how long a player has been in the league and whether he's made an All-NBA team or won Defensive Player of the Year. For simplicity, focus on players with 10-plus years of service, because those guys can always be offered the 35% max, the highest tier.
That 35% doesn't mean the player earns 35% of the cap every year of the deal. It only sets his salary in year one. That first-year figure becomes the base, and his annual raises, up to 8% depending on the type of deal, are calculated off it.
Here's the simple version, just hypothetical math. Say the salary cap in year one is $100M.
The player's year-one salary is 35% of that cap, so $35M. His raises are 8% of that first-year number which is locked in at $2.8M a year for each year. Over a five-year max, it looks like this:
Year 1: $35M
Year 2: $37.8M
Year 3: $40.6M
Year 4: $43.4M
Year 5: $46.2M
This is also why, when a player signs an extension, you always hear about his "projected" salary. We don't know his actual number until we know the cap in the contract's first year. Donovan Mitchell just signed a four-year max extension, structured as three years with a fourth-year player option, that begins in 2027-28. But nobody knows what the cap will be that season. It's currently projected to rise only 5.5%, so we can estimate his deal today, but we won't know the real figures until next summer, when the official cap is announced.
So, again, why does this matter?
When the cap was expected to climb 10% a year, it was rising faster than player salaries. Now that script has flipped. The cap is crawling, but salaries tied to those old 8% raises are climbing faster than the cap itself. That leaves teams with less optionality to improve their rosters in future seasons
Do the math on the squeeze. Say you have two 35% max players eating up 70% of your cap. That leaves 30% for everyone else. Under a $228M cap, that 30% is $68.4M to build out your depth. But if the 2029-30 cap comes in at just $193M as currently projected, that same 30% is only $57.9M. Same roster structure, $10 million less to work with.
Now, teams can exceed the cap, and this is where terms like the luxury tax and the first and second aprons come in. The luxury tax threshold always sits at 121.5% of the cap, and teams can go past even that if they're willing to pay for it. I won't drag us into the weeds on the aprons. The point of the 30% example isn't the exact accounting, it's just an example: less cap means less future money to improve the team. Pair that with player salaries now outrunning the cap, and every front office has to stop and reassess where it stands.
Remember that Mitchell extension? It's a 35% max, but because his raises outpace the shrinking cap, here's the share of the cap he's projected to eat up as the deal goes on:
Age 31: 35%
Age 32: 36%
Age 33: 36.83%
Age 34: 37.49%
Is Donovan Mitchell going to be worth $75.5M, or 37.49% of the cap, in his age-34 season? No. And that's the bind. When the cap isn't climbing the way everyone assumed, those back years get ugly. If you're a contender trying to max out your title odds right now, you bite the bullet and worry about it later. But hey, that's the next GM's problem, right?
But let's get back to Jaylen Brown, and the next reason he got traded.
Reason 2: Analytics and Team Building Philosophy
The new cap landscape forces every team to ask hard questions and take an honest look at its championship window. This offseason, it looks like a lot of teams got better. So what are the Celtics' true title odds now? And if the front office decides this group isn't good enough to genuinely contend, how does it improve the roster with less flexibility down the line?
People say the nerds won. But the analytics on Jaylen Brown have been the same for six straight seasons.
Start with the metric itself. Estimated Plus-Minus, or EPM, is an all-in-one number that estimates a player's contribution to his team in points per 100 possessions. It pulls from box score, play-by-play, and player-tracking data, and it accounts for every lineup Brown has ever played in: who he shared the floor with, who they faced, and how those groups performed with and without him. In other words, a lot of information goes into estimating a single player's impact.
There was a quote making the rounds that Jaylen Brown was the seventh-best player on the Celtics. Jaylen Brown grades out as the fifth most impactful player on the roster, behind Tatum, Queta, White, and Pritchard. But here's the context that matters: Brown also carried an enormous load. Last season, 35.2% of Boston's possessions ended in a Brown shot, free throw attempt, or turnover, one of the highest usage rates in the entire league.
That usage cuts both ways. If Brown's role were reduced, his impact metrics could actually climb. Fewer possessions could mean better efficiency on offense and more energy to pour into his defense. So while I don't think any serious analytical person would call Brown the seventh-best Celtic, I do think it's fair to call him overvalued relative to his contract moving forward. And that's the real question the Celtics have to sit with: what is Brown producing in his current role, and what are they paying for it?
For most of the past six seasons, Brown has finished around a +2.5 EPM. That's roughly the 40th most impactful player in the NBA. That's a genuinely good player. But he's entering his age-30 season. From here, the reasonable expectation is that he holds steady or slowly declines, while his salary keeps climbing. The line in the chart below is his EPM by season, and the bars are the percentage of the cap his contract eats up.
Young players are great because they can provide surplus value. High impact, low salary. The Celtics won a title when Jaylen Brown was making 23.4% of the cap. Can they win another when he's making north of 35%? That gets a lot harder, especially with everything from Reason 1 in play, the cap no longer rising the way anyone planned.
So the Celtics had a decision to make: stay the course or retool.
Look at the hypothetical chart below. I'm not claiming this is exactly how it plays out. It's an illustration to frame the thought experiment. The Celtics are past the peak of their championship window. They could still win in theory, but the odds are low and only getting lower. At the same time, the value of their assets erodes as those players age and get more expensive. Every year you stay the course, you're a little worse and the future build gets harder.
I believe the Celtics looked at that and admitted the hard truth: this team, as built, isn't good enough to be a real contender. So they chose to retool. Sell early, while the assets still hold value, and turn them into future pieces. You give up a sliver of your already-slim title odds right now in exchange for a much better shot down the road.
Yes, Boston traded Jaylen Brown, and emotionally that's crushing. Fans built a connection with him. So did teammates, staff, the arena workers, the city. That part just sucks, because Brown is a good player, and this strategic game of sliding pieces around the board only works if you ignore that the pieces are people.
Set the emotion aside, though, and the basketball question is sharper than it looks. Did the Celtics actually get worse? A little, probably. Did their championship odds crater? No.
There's a stylistic cost. Boston already didn't pressure the rim enough, and they just dealt away one of their best players at doing exactly that. With Paul George and Mitchell Robinson in, this team likely leans even harder into threes and offensive rebounds. George won't match Brown's availability, but the Celtics are a regular-season juggernaut. They finished fourth in the league last year, return most of the roster, get Tatum back from injury, add George and Robinson, plus a year of growth from the young core. Are they really that much worse this season?
Probably not much. In both the stay-the-course and retool scenarios, this team makes the playoffs and most likely bows out in the first or second round, with maybe one conference finals run in there somewhere. The ceiling was roughly the same either way. The retool buys optionality and improves future championship odds.
Staying the course had its own trap. Brown's extension talks were coming. Offer the max, and you deepen the exact problem this whole article is about. Don't offer the extension, and you've got a disgruntled star and a locker room question. It gets hairy fast.
Instead, Boston came away with real future value. Under the new lottery rules, that 2028 first, the more favorable of the Clippers and Sixers, is a genuine asset. The 2031 Sixers pick is unprotected. Both seconds land as the most favorable of three teams picks. Fans love pick quantity, but all picks aren't created equal, and a second-rounder that hits near the top of its range lets a contender add cheap, cost-controlled talent without paying first-round money. I'd take these two firsts over three Spurs firsts, or three Thunder firsts, without much hesitation.
So, the two questions I keep coming back to.
If the nerds won, why wasn't Jaylen Brown traded years ago? Why now?
And if this trade was an abomination for Boston, why didn't anyone beat it? If the Celtics got fleeced, if this was such obviously bad value, what does it say about the other 28 teams that watched Brown sit on the market for weeks and never topped the offer?
The analytics on Jaylen Brown never moved. He's the same very good player he's been for six years. What changed is the ground underneath him: a stalling cap, an aging player, a salary climbing higher every season, and a championship window quietly closing. In that environment, Boston had to ask itself a hard question about who they really were and where they were actually headed. They decided it was better to look forward and maximize the future than to keep slowly eroding the present.
Further content to explore
A great reference that helps explain all the intricacies of the CBA. Bookmark to look up anytime you have a question.
This is where I got the EPM data. This is a subscription site, but I feel like if you enjoy stats, this is one of the best subs you can do.
All cap information comes from this site. It's a must have for looking up contracts and all things salary cap
This is a Substack that requires a subscription, but I wanted to share as Jeremias Engelmann writes it who formerly worked in NBA analytics for the Suns and Mavericks. He breaks down the Jaylen Brown trade and gives you a sense of what an actual person that worked for a NBA analytics department thinks
Unfortunately another sub, but I wanted to give them a shoutout as they were the inspiration for this piece after listening to them discuss how player salaries are now out pacing the salary cap. My favorite basketball podcast.
Inside the Supermax: How the NBA’s Economic Boom Redefined Player Contracts
A free article that does a good job at explaining max contracts.