The bandwagon follows the star, not the trophy

On Thursday night in Los Angeles, the Brewers beat the Dodgers 6–4 and finished a four-game sweep. Two straight championships, the biggest payroll in baseball, and the run ended without a single win in the series.

So what happens to all those Dodgers fans?

The usual answer is that the bandwagon thins out. Everyone knows how bandwagons work. A team starts winning, people who weren't paying attention start paying attention, and when the winning stops, they drift off to the next thing. It's one of the few things in sports nobody argues about.

We wanted to see it in the data. We went back through ten years of attention to every team in the NFL, NBA, MLB, NHL and MLS, and measured each team's share of its league's attention, season by season. Then we looked at what moved it.

Why share? Because a fan's time is finite. Every hour spent on the Chiefs is an hour not spent on the Bills, or on Netflix. Share is the closest thing sports has to market share: it shows who is winning the competition for the same hours, and attention is the raw material for everything a team sells, from tickets and jerseys to sponsorships and TV deals. Raw totals rise and fall with the whole internet. Share tells you who is actually gaining.

The bandwagon is real. It just doesn't follow the trophy. It follows the people.

What a title is worth

Start with the champions. We tracked 40 of them, every title winner in the four big leagues from 2015 through the 2024–25 seasons, and compared their share of attention the season after they won with the season they won it.

The typical champion gained 8%. That's it. A normal team's share moves about 9% in an ordinary year, up or down, from injuries, schedules and luck. Eleven of the 40 champions actually lost share the season after their parade.

There is one place a title clearly builds something, and it's a little surprising. In basketball and hockey, first-time champions, and teams ending waits of 40 years or more, gained a lot. The Bucks, Nuggets, Thunder, Blues, Golden Knights and Capitals all jumped well beyond a normal year. The typical one in those two leagues gained 33%.

In baseball and football, the most famous droughts in sports bought almost nothing. The Cubs waited 108 years for the 2016 title. The next season, their share of baseball's attention fell 21%. The Eagles won their first Super Bowl and lost 26%. The Rangers won their first World Series and lost 10%. Across the six first-time and long-awaited winners in those two leagues, the typical change was a decline.

That matters this month. The Brewers have never won a World Series. The Rays haven't either, and Cleveland hasn't since 1948. History says a title would be a great night in Milwaukee, or Cleveland, or Tampa Bay, and not much of a bandwagon afterward. (As a Cleveland fan, I'd take that deal.)

What a person is worth

Now look at what happens when a star moves.

When Tom Brady went to Tampa Bay, the Buccaneers' share of NFL attention jumped 84% in one season. The Patriots' fell 39%. When Kawhi Leonard signed with the Clippers, their share rose 44%. When Shohei Ohtani joined the Dodgers, theirs rose 19%, before he'd won anything there.

And when Lionel Messi joined Inter Miami in 2023, the club went from about 9% of all attention to MLS teams to 47% for the season. That's not a typo. Three years later it's still at 22%, roughly two and a half times where it was before he arrived.

Departures are just as loud. When LeBron James left Cleveland in 2018, the Cavaliers' share of NBA attention fell 47% in a season. (Cleveland did not need the data to know this.) After the Mavericks traded Luka Dončić, their share dropped 45%, and that's with the first pick in the draft, Cooper Flagg, arriving a few months later.

A few championships moved a fan base as much as Kawhi or Ohtani did. None came anywhere near Brady or Messi.

The cleanest test: the Chiefs

The Kansas City Chiefs gave us something close to a lab experiment. They won the Super Bowl in February 2023. Seven months later, Taylor Swift showed up at a game.

Here's what their share of NFL attention did that fall. Opening night, as defending champions, it spiked. Then, within two weeks, it fell right back to 2.8%, the same as the season before they won. The title had already worn off.

Then came September 24, Swift's first game. Their share nearly doubled, and it never went back. The Chiefs averaged 4.5% the rest of that season, 4.6% the next, and 4.2% this past season.

The championship didn't do that. One famous fan in a suite did.

Rings vs. people

Put two dynasties side by side and the pattern is hard to miss.

The Warriors won three titles in our window, plus one just before it. Over that stretch their share of NBA attention fell by more than half, from 12.3% to 5.9%. The Kevin Durant years came and went. The rings didn't hold the crowd.

The Dodgers won three titles too. Their share went up, from 4.7% in 2016 to 6.1% this season, the highest of the decade. The biggest single jump wasn't a title year. It was 2024, the year Ohtani arrived.

So the Dodgers' fans aren't going anywhere. Not because of the rings. Because Ohtani is under contract through 2033.

Why it matters

Teams spend enormous money chasing championships, partly on the theory that winning builds a fan base. The data says winning mostly builds a parade. Outside of a first title in basketball or hockey, it's a one-season bump that's smaller than ordinary noise.

People are different. A star changes a team's share of attention overnight, and the effect lasts as long as the star does. That makes a star the closest thing in sports to a durable attention asset, and it changes how a few big debates look.

Baseball's owners and players head into labor talks this winter, and some owners want a salary cap. Whatever you think of that, the thing a cap would make harder, a team going out and getting the next Ohtani, is the thing that moves attention most.

And for MLS, the lesson cuts both ways. Messi did more for one club's attention than any title in any league we measured. When the biggest stars in our data left, their teams lost 39% to 47% of their share in a season. Inter Miami draws more than a fifth of all the attention in the league. Someday it will find out what that number looks like without him.

How we measured it: each team's share of all attention to the teams in its league during the regular season, compared season to season, 2015 through 2026. Using share rather than raw totals removes changes in overall online traffic. Champions are compared with the season after their title. The star moves are the biggest arrivals and departures of the period, not a complete list, and a few have other things going on at the same time, so read them as strong hints rather than controlled experiments.