Mainz fans are different. Nicolai Müller couldn’t process it. On the last day of the 2012 Bundesliga season, Mainz 05 were down 3-0 to Borussia Mönchengladbach…and fans were celebrating. The budding striker, who had joined Mainz 05 at the beginning of the season, was furious. The ultràs in the stands – the second biggest standing section in Bundesliga after Borussia Dortmund’s Yellow Wall – had just announced another goal for Mainz 05. The spectators around them joyfully cheered. On the pitch, it was still 3-0.

Müller thought the fans were mocking the team that finished 13th in the table that year, their third consecutive season in the first division. His teammates tried to calm him. The fans were making their own fun, as the team was unable to provide any that day. That’s the Karnevalsverein.

But while even the most passionate football abstainer knows there’s a famous team in Munich, those (few) who don’t care for football may never have heard of a football team in Mainz. They will have heard of carnival, though (actually, the term used in Mainz is Fastnacht and Karneval refers to Cologne. The term Karnevalsverein was given to Mainz 05 by outsiders). The Rosenmontagszug, a carnival parade through the city of Mainz on the Monday before Ash Wednesday, attracts twice as many spectators as Mainz has inhabitants. Half a million people crowd the 2000-year-old town on the River Rhine in what is called the “fifth season, or Narrenzeit, the “time of the jesters”. Mainz carnival is an ingenious mixture of history, tradition, music, fun, sarcasm, politics and alcohol. Full-time jesters spend three-quarters of the year preparing costumes, dances, songs and speeches for the “crazy days”. It may be a jest, but it’s a very serious affair, too. And it splendidly associates with football, the game played by eleven players. Eleven is the sacred number of carnival, which starts November 11.

When Mainz 05 started aiming for promotion to the first league in 2001 under coach Jürgen Klopp, fans and journalists regularly called the Rhinehessians “just a carnival club”, one not to be taken seriously. Klopp, who later moved to Borussia Dortmund and now at Liverpool, was a player out with injury when the club’s bosses made him coach in February 2001. With him the club avoided relegation in 2001 and the following season missed promotion by one point. One year later they missed it by one goal.

In 2004, just in time for the club’s 100th anniversary in 2005, the Karnevalsverein managed the jump to the first league. The city brimmed with joy. The adored “Bruchweg” stadium (which roughly translates as “broken way”), arguably too small for Bundesliga requirements, hastily received some additional stands and it became next to impossible to get tickets for matches. 05 fans took to camping in front of the ticket-shop at nights to be first in line the next morning. Manager Christian Heidel, who had to step over them when he arrived at his office the following morning, went and handed out cups of tea to them. That’s the Karnevalsverein.

Mainz’ first spell at the top lasted but three years. Klopp set sail for Dortmund before the still-viable dream of promotion could come true again, but in 2009 new coach Jörn Andersen brought the jesters back to Bundesliga – only to be replaced soon by another homegrown coaching talent: former U19 coach Thomas Tuchel (also now at Dortmund).

The second spell in the first league was to commence with less of the jest and more of a business spirit. Sometimes after a couple of glasses of Riesling, Heidel and president Harald Strutz would face the enduring image of a carnival club with a sigh. Mainz had started their career in the first tier German football as everybody’s darling, cute and lovable and a bit crazy. But the zero-fivers now wanted to stay and carnival didn’t seem enough.

It wasn’t. Over the course of two years the idea of a new stadium, already considered after the first promotion, became reality in Coface Arena (now Opel Arena). In the middle of fields of wheat and strawberries, reached on foot over partly muddy tracks, the “jewel box” (Schmuckkästchen) was presented to the fans. Supporters marched from the old venue to the new, bringing a crate said to contain the old stadium’s spirit, but the spirit of Bruchweg could not be transferred that easily. Still, from the fans’ march to the 100-year-old cathedral choir, from the then-presiding prime minister of Rhineland-Palatinate, Kurt Beck, being booed for his sympathy to arch-rival 1.FC Kaiserlautern, to the bishop of the catholic diocese of Mainz, Cardinal Karl Lehmann, fresh from an operation in a wheelchair being met with a standing ovation, the inauguration of Coface Arena was typical Karnevalsverein.

Still the jest was slowly trickling away. Mainz 05 had to balance retaining their unique reputation for being slightly different, slightly crazy, and very lovable with vying with 17 other clubs for a permanent place in Bundesliga. After qualifying for Europa League for the first time in 2016, the business side may be considered accomplished – but what happened to the carnival spirit?

Mainz 05 is one of the few Bundesliga clubs that’s still a members’ association. When Heidel, the manager of 25 years, left for Schalke 04 in 2016 (something previously as unthinkable as Captain Kirk leaving the Enterprise) a new era was predicted. Modern football reached out its claws for the jester as well as for the king and queen. Mainz 05 recently invited fans and members to discuss a major change in the club’s governance structure. Should the professional team be transformed into an independent capital corporation as the majority of Bundesliga clubs have already done? Strutz, long-time honorary president, would love the well-paid position of full-time president.

Yet the carnival spirit is still alive. And kicking – as befits a football club and its supporters. Mainz supporters are divided into two types, who are not always in love with one another. There are the old-timers who went to games when 05 was still in the third division. They grew old with the club and their season tickets are cherished heirlooms. To get hold of one of those on the south stands you best study obituaries. These pioneers of Mainz football sometimes look askance at the young ultràs in Rheinhessen-Tribüne, the west stands, which overflow with imagination, songs and tifos every home game. Their continuous singing tends to annoy the old hands who prefer to voice their support in three letters – F S V – for Football Sportsclub Mainz 05. But the young ones provide a spirit and passion still akin to that which lead to the first Rosenmontagszug in 1883.

Both sets of Mainz fans are politically active and passionate about anti-racism, anti-homophobia and whatever anti- they might encounter. From the Romans to the French occupation to the tourists now drawn from all over the world to examine that Roman heritage (which pops up with artefacts whenever a new parking garage is built) the lively city maintains an open and welcoming attitude. Its football fans are no exception. Neither is its club.

The current squad brings together players from 14 different countries. From irresistible Argentine striker (technically all-rounder) Pablo de Blasis to Leon Balogun, the Nigerian international battling it out in defence, to Japanese forward Yoshinori Muto, every continent and country is welcome in Mainz. Listening to staff and players at public training twice a week, fans may get the impression they are visiting the UN.

Then there’s the club itself. Obviously Mainz isn’t the only decent club in Bundesliga, but there are a few recurring traits that mark the Karnevalsverein as different. The most obvious is – or used to be – Heidel’s way of handling transfers. If every club was like Mainz 05, journalists would starve for news during the transfer window. With Heidel there was never a leak, never an unfounded rumour and never a scandal. The quiet, which had lasted 24 long years, was broken one Saturday in February 2015, when his son told a friend that coach Kasper Hjulmand was about to be sacked. That friend told Twitter. It was an event unheard of at Mainz 05 and for many it marks the beginning of the unimaginable: Heidel leaving Mainz. But the Heidel-style of keeping transfers (or anything squad-related) away from the public eye looks to be continuing under his successor Rouven Schroeder. That’s still the Karnevalsverein.

This sense of fairness and responsibility shapes the way players are treated. Todor Nedelev, bought in 2014 from Bulgarian club Botev Plovdiv, struggled to adapt to Bundesliga even before he broke his foot. Generally unhappy at Mainz, the 23-year-old is now on loan back at Botev. Heidel’s comment that “he needs a change of air” reflects how Mainz feel responsible for their young players. Talents who come to Mainz while still in school are encouraged to finish with the highest German degree, Abitur, to improve their chances if football somehow doesn’t work out for them.

Older players are treated the same. Mainz midfielder Elkin Soto thought he was playing one of his last matches in the red-and-white shirt when going up against relegation-battling Hamburger SV on May 3, 2015. After nine years with the carnival club he was set to leave for his homeland, Colombia. 30 minutes in, a collision with Hamburg’s Rafael van der Vaart had Soto down screaming. Every ligament in his left knee was ruptured, the kneecap dislocated. “I never saw something like this before,”Heidel told the press. “The knee wasn’t in its place anymore.”

Such an injury likely means the end of a career. Soto was without contract and set for South America. Instead, that evening Mainz 05 announced they were extending his contract, and he’d undergo all the necessary surgery and therapy in Germany with his family financially secured. Almost exactly one year later, six minutes into additional time in the final match of the season, Mainz coach Martin Schmidt signaled for a final substitute. The players explained to the referee that this was no normal sub. To deafening cheers from the stands Elkin Soto entered the pitch and played one final minute for the club which had never let him down. He is back in Colombia now and yes, he still plays football.

When asked about how well the club had treated him after his horrific injury, Soto simply stated, unsurprised: That’s the Karnevalsverein.

Finally, the club knows how to treat their fans. In May 2016 Mainz 05, for the first time in their history, secured a place in the table for Europa League group stage (having failed to pass the qualification round two times before), and fans were understandably overjoyed. The club, via social media, invited fans returning from the match in Stuttgart to a reception at the old and traditional Bruchweg stadium. We went there by the hundreds and gave them a welcome we’d tell our grandchildren about. Flares, which for once weren’t evil pyrotechnics but described as “brilliant beacons” in the papers, lit the night while fans sung chanted and cheered. Beer, soft drinks and wine flowed for everyone and for free. We know how to party in Mainz. Remember – it’s just a Karnevalsverein.