The Milwaukee Brewers learned a valuable lesson last week.

Don’t mess with the “L” flag.

It might have been a coincidence that the Brewers were swept in four games by the Los Angeles Dodgers in the National League Championship Series after taking a team photo with the “L” flag following their division series-clinching win over the Chicago Cubs.

The “L” flag did not factor into any of Shohei Ohtani’s three majestic home runs Friday in the Dodgers’ NLCS-clinching win, or any of Ohtani’s 10 strikeouts over six scoreless innings. And surely the “L” flag had nothing to do with one of their fans losing her job after going viral for threatening to call ICE on a Dodgers fan who happened to be a United States citizen and a veteran of two wars.

But considering all the bad things that happened to the team with the best record in baseball after the “L” flag incident at American Family Field, it makes you wonder.

The “L” flag, for those not paying attention, is the sad cousin to the “W” flag, which Cubs fans fly at Wrigley Field after wins. The tradition began in the 1930s when the Cubs began flying a “W” or “L” flag atop of the center-field scoreboard to let riders on the ‘L’ know whether the team had won or lost that day.

It was a tradition that few players thought about until 1998, when Cubs closer Rod Beck suggested flying the “L” flag was “bad karma.”

“I’m not blaming anything for it,” Beck said. “But I’m a believer in positive energy and karma. When you lose a ballgame and fly an ‘L’ over the park, you leave a bad aura around the ballpark and it can go all the way into the next day.

“They do it, obviously, so the people on the (train) can see whether we won or lost. It’s a good theory, but maybe they can change it to where they can drive by and when they don’t see any flag they can assume it’s an ‘L.’ Or maybe they can fly a `W’ for “Wanted to win.”

Beck was not serious, but he was a man who enjoyed stirring debate.

“It’s not a strong theory,” he told me. “But it’s something to make you think.”

Beck’s suggestion was widely ignored until 2008, when the Cubs marked the 100th anniversary of their last championship season and had a team that was good enough to end the drought. In July of that season, with the Cubs in first-place, team executives considered the idea of not flying the “L” flag after losses but decided to leave the tradition intact. Instead of blaming the flag, they turned their attention to the Billy Goat curse.

Before Game 1 of the 2008 NLDS against the Dodgers at Wrigley Field, unbeknownst to general manager Jim Hendry and manager Lou Piniella, Cubs executives Crane Kenney and Mike Lufrano invited a Greek Orthodox priest onto the field for a pregame ceremony to bless the Cubs dugout with holy water and remove the curse.

Long story short — it didn’t work.

“Now I’m just another Cubbie occurrence,” the priest, Rev. James Greanias, told the Chicago Tribune that night.

The Cubs were swept in three games by the Dodgers and would not get back to the playoffs for seven years.

The “L” flag went back into semi-obscurity until 2017, when Brewers fans began bringing them to what was then named Miller Park in response to a mass migration of Cubs fans to their ballpark for Cubs-Brewers games. It really took off in 2018, as the Cubs-Brewers rivalry began to heat up under Brewers manager Craig Counsell.

But trolling the Cubs was typically something done by fans, not the players.

After the Brewers beat the Cubs last week in Game 5 of the NLDS, the Brewers brought an “L” flag to the field, and reliever Trevor Megill held it high in the team photo. The Brewers’ X account, @Brewers, then trolled the Cubs by tweeting the photo and creating an AI-generated video of an “L” flag covering the iconic Bean, adding the caption “HEY CHICAGO, WHADAYA SAY?”

MLB’s X account, @MLB, added to the story by tweeting their own video with a laughing emoji.

It was all in good fun, though the backlash from Cubs fans suggested many weren’t amused by the trolling. Counsell and Cubs players had congratulated the Brewers and complimented the team after losing Game 5, so to some it seemed like the trolling by Brewers players and the organization’s social media employees was classless and beneath a professional sports team.

Would the Cubs have mocked the Brewers had they won? Doubtful. Would their social media team have piled on? Possibly.

We’ll never know.

Either way, the controversy figured to die down until next season when it would obviously be brought up again when the teams met again. But the Brewers lost the first two games to the Dodgers at home, and their fan who threatened to have a Dodgers fan arrested by ICE quickly became famous. Cubs fans helped amplify the video, which quickly became a national story.

When the Brewers lost Game 3 at Dodger Stadium, more fans jumped in, and included the woman referred to as “Brewers Karen” as part of the “curse of the ‘L’ flag.” Game 4 became an instant classic thanks to Ohtani’s performance, and the Brewers’ dream season ended in disappointment. The team scored four runs and had only 14 hits in the four games.

“The pitching performances by the Dodgers basically put the hammer down,” Brewers manager Pat Murphy said afterward.

True enough. The Dodgers were the superior team and proved it in the NLCS. They’ll head into the World Series as favorites over the Seattle Mariners or Toronto Blue Jays, and MLB can only pray the series isn’t as short and lopsided as the NLCS turned out to be. A ratings flop seems inevitable if it’s another sweep.

The “L” flag will no doubt return to American Family Field when the Cubs and Brewers play there in 2026, and it’s now part of Brewers team lore, just as the curse-busting episode of 2008 became part of the Cubs lore.

Kenney later called it “one of the dumbest things” he had ever done, taking blame. Will Megill and the Brewers ever admit that holding up an “L” flag for a team photo was one the dumbest things they’ve ever done?

Check back in spring training.