HOFFENHEIM, Germany -- There is a battle raging in German football. It has been fought with words and emotions, and occasionally turns ugly. RB Leipzig dominate the headlines after their remarkable ascent, using a smart mix of money and knowledge to move ahead of their established Bundesliga rivals. Almost every week, they meet with hatred. Some followers of the game feel left behind. For each new club, an old club, soaked with tradition, has to go.
Meanwhile, sheltered from the rush of city life in the rolling hills of the Kraichgau region, TSG 1899 Hoffenheim have also gatecrashed the party. As their name indicates, Hoffenheim have a long history, but they are a village-based club whose rapid ascent from the fifth tier to the top flight was completed between 2000 and 2008.
Kraichgau is a quiet area, one where time is not an enemy but an ally, but Hoffenheim do not dwell in the past. With the help of local billionaire Dietmar Hopp and computing power, they are stretching the limits of football, and have become Germany's first "beta" club -- leaning heavily on stats and data.
Peter Gorlich, a Zuzenhausen local, has been Hoffenheim's executive for sports and communication since October 2015, when he took charge of the club amid a major crisis.
"You need to be distinctly aware that you will always have temporary phenomena in football, and you must know where you are coming from and where you want to go," the 49-year-old told ESPN FC, stressing the club's focus on a "super structure."
"You need to make sure the contextual factors in this system remain stable and that you run that system with the required humility. You should not stop pressing ahead with that intense and difficult academy work just because things are going well."
Things are going well now. This term, they have picked up 38 points from 22 matches. Last season, they only won 37 all season. They are competing for a place in Europe.
In late January, Hoffenheim, who were then the only unbeaten side in Europe's top five leagues, travelled to Leipzig. With 18 minutes played, midfielders Karim Demirbay and Sebastian Rudy won a ball inside their own box following a Leipzig corner; 12.88 seconds later, the ball hit the back of the net. It was a textbook move.
Rudy, who will join Bayern Munich this summer, carried the ball forward, and passed it to Demirbay, who 5.76 seconds after winning possession was close to the halfway line. He received it, and looked up to see teammate Nadim Amiri breaking away on the other side of the pitch.
Two touches, one pass. Demirbay cut open the Leipzig defence. Amiri played a one-two with Andrej Kramaric, and had an open goal in front of him.
In the end, Hoffenheim lost the match, but the goal stands as a perfect example of Nagelsmann's team this season -- and how Hoffenheim prepare their players.
"What does this player have to play a ball like this? It's not only good feeling -- there are many aspects up here," Gorlich says, pointing to his head. "It's about speed of execution, and you can learn speed of execution through automation processes. But you need to know what the starting point is. We do that in the Footbonaut, we do that in the Helix. That's where we render assistance."
It all takes place in one of the buildings on the club's training base, an old castle that had been a nightclub in the 1970s and 1980s where the likes of Led Zeppelin, the Sex Pistols and The Stranglers would be heard. The club's technical building, which will get its own research lab later this year, is right next to the castle. Inside there is the Footbonaut, a Speed Court, the Helix and the Wiener Testsystem, which centres on computer-based psychodiagnostics.
"You get an incredible wealth of data," Gorlich says. "You can carve out motivational structures. How does a player cope with recognition? How does he handle power?"
Data is kept not only for players but most people at the club, whether coaching staff, physios or the sporting hierarchy. Gorlich's own history is one example -- he came through the ranks of the academy, first working as a goalkeeping coach and later spearheading the youth department.
Others have followed similar paths and, inside the academy, young coaches and leaders are waiting for their time, refining their set of skills day in, day out.
"Recognition, power, claims to leadership, approach to leadership -- you can get that data. That's classical behavioural psychological data. You can work with it," Gorlich says. "We also make tests for decisions under pressure. Do I make the right one or the wrong one? How long does it take?
"It is a demanding environment for coaches, managers and players. It's wild for them. The ball contact times get shorter. The compression of the pitch gets bigger. They run more. You can close spaces faster. You need to make quicker decisions because the opponents attack you earlier."
Those tests are carried out in the giant indoor hall.
The Footbonaut, which costs around €3 million to build at its most basic, is a 20x20-metre cage with four machines firing footballs at different speeds and trajectories towards players, who receive the ball, have to control it and pass it into one of 64 blinking target squares. In Germany, it rose to prominence when Borussia Dortmund used it during their breakout years in Europe earlier this decade. These days, in part because of the three-match weeks they often face, it's rarely used at Dortmund other than for rehab training.
While training in the Footbonaut is carried out, and the data is collected, stadium noise -- adjustable from a standard ground to the roar of a fierce Westfalenstadion loudly shouting at the opponents -- booms out of the loudspeakers.
"It intensifies the pressure situation," Rafael Hoffner, head of Hoffenheim's sport-IT-innovation department, says.
The system gives players the chance to internalise an important part of Nagelsmann's idea of football: Two touches, orientation.
"I prefer to finish more attacks, rather than rushing to finish one or two," Nagelsmann, now 29, recently told Deutsche Welle. One of those attacks gave them that 1-0 lead at Leipzig in January.
Inside the Helix, peripheral vision is tested, with players having to track movements on a 180-degree circle screen.
"Who's your friend and who's your opponent? What does he do? Which opponent moves where? And where can I create a passing situation? And where can I outnumber them? Those 'gamification' processes are crucial for a keeper. What happens around me? That's crucial for a holding midfielder," Gorlich says.
The speed court is basically a digitalised version of the Life Kinetik idea. Gorlich simplifies this as "juggling balls, running without moving, the multiplication table."
All the data goes into a product developed by SAP. It's called Sports One and it collects everything. Hoffenheim are the beta club. It's here where it's all tested, discarded, changed, implemented.
The club have already tested sensor technology inside those test and training machines, and -- citing the 2013 novel "The Circle" by Dave Eggers -- Gorlich praises technology as the future. "It will be small," he says, explaining that you will be able to throw a small camera into a corner, and stick sensors into shoes, and they will give you the data needed to improve the processes of regeneration and rehabilitation. It's the measuring of football.
For players, the process inside the academy starts at a young age. "Competitive sport starts in the under-12 teams," Gorlich says. "That's when the casting show starts. You need to be aware of that."
The club offers regional training sessions even earlier than that and, as the players get older, draw a wider circle to scout talent while others are released. Some are offered the opportunity to train at other clubs within a regional foundation called Anpfiff furs Leben.
It's a ruthless filtering process, but Hoffenheim are aware that they have a social responsibility. "They give us their youth for a dream. We know that we won't be able to fulfil every dream -- not because we don't want to but because sometimes it does not work," Gorlich explains.
"In my eyes, an U17 player is a pro who still attends school. Regionality is paired with internationality at that stage," Gorlich says. "We've got players from Austria, Sweden and the United States [16-year-old defender Jean-Julien Foe Nuphaus] in our U17 team now. You scout internationally, get them into the Hoffenheim system as early as possible so they understand it and you hope that someone arrives at the top."
Over the years, many have emerged from the academy, including current first-team players like Germany international Niklas Sule. Previous graduates include Gorlich, Nagelsmann, 37-year-old director of professional football Alexander Rosen and most of the coaching staff. These days, the ex-academy products form the backbone of the club.
Sule became the first academy player to win a Germany cap but -- like Rudy -- the defender will move on to Bayern in the summer. "Sule's path at Hoffenheim stops here because he's seeking a new challenge," Gorlich says. It's part of the club's business model. They are developing technique and personnel for the "sport game football," as the executive likes to call the business.
Over the past two seasons, the club have received around €50m more than they have spent, in part because of Roberto Firmino's move to Liverpool in 2015. When they began their rise under the current RB Leipzig sporting director Ralf Rangnick and current Hamburg director of sport Bernhard Peters in 2006, benefactor Dietmar Hopp splashed out millions and millions, only firing up the protests among traditional clubs' fans. They felt that the SAP founder had bypassed the 50+1 rule, and worked to bring about its end.
Over the years -- partly because of a perceived loss of direction in the club's professional department, where all stability was lost when Rangnick walked out in early 2011 -- Hoffenheim have to some extent become an accepted member of the league.
Hopp no longer is in the spotlight, despite taking over the club in 2015, and throughout the years Hoffenheim lacked a prominent face. This has changed with Nagelsmann, who is exemplary with regard to the club's desire to focus on their academy and love of data.
He joined Hoffenheim in 2010, at that time still run by the Rangnick-and-Peters partnership, and took on several roles in the club, working as an assistant coach for the professional team, as well as the head coach for the U19 team, which he guided to the 2014 Bundesliga title. In 2015, he began classes at the German FA to win his full coaching credentials.
In October 2015, coach Markus Gisdol, the hero of a 2013 relegation battle, was sacked after only one win from 10 games. Veteran Dutch coach Huub Stevens agreed to join the club until the end of the season, when young Nagelsmann was set to take over.
Stevens lasted 10 match days. During that time, Hoffenheim picked up one win, five draws and four defeats. They were stuck deep in the relegation zone, and the Dutchman stepped down for health reasons. Despite still working on his coaching qualifications on a course in Hennef, the young Nagelsmann stepped up to become the youngest coach in Bundesliga history aged 28.
"It was a delicate situation. You've got a responsibility for your employee. You risk burning him in the fire," Gorlich says. "One factor is important -- we always talk about the power of innovation. So, what allows you to make such a decision? There were other coaches on the market, but we knew how Julian Nagelsmann would cope with stress situations, and then you start to weigh the risks.
"Not only your good feeling, but you also consult the facts. If you know about the motivational structures and how stress-resistant he is and how he copes with it and whether you trust him to stand in front of a rattled squad and understand them. We were convinced and we told him: 'Julian, we'd do it. Would you do it? Do you trust yourself to do it?'"
Hoffenheim had collected enough data to know the answer to that question. The super structure was in place, Nagelsmann took over, successfully battled relegation and -- a year on from his appointment -- has manoeuvred his team into a very comfortable position in the Bundesliga table. In their ninth year in the upper tier, they could qualify for Europe for the first time.
"It's likely that Julian Nagelsmann won't stay here forever," Gorlich added.
Hoffenheim are aware that success and the spotlight might only be temporary, but they are happy with their role. They have already been the trailblazers for the fall of the 50+1 rule; now they look like the trailblazers for the digital transformation of German football.
Over in Leipzig, Rangnick already is working on his next project. It's bankrolled by Red Bull rather than Hopp, and with the end of 50+1 nearing in German football, more investors will come into the market.
"At the end of the day, we are a commercial enterprise. This is a business case," Gorlich says. "We try to monetise sporting success, but also innovations, the use of technology. Just as we try to get a transfer fee for a player, we also try to find tailormade offers for our sponsors."
There is a battle raging in German football. But one side appears to be fighting a lost cause.
Where other clubs draw their strength from a rich tradition, Hoffenheim live and breathe their vision of the "sports game football." Attendance figures at their stadium have gone up this season too. Time is not an enemy, but an ally.