The man reportedly set to take charge of Serie A club AC Milan has a long history in German soccer. The 62-year-old's work across the Bundesliga and elsewhere has influenced a generation of German coaches.
In 1998, Ralf Rangnick, as coach of second-division side Ulm, stunned the German football world by appearing on a popular television sports show and explaining the back four and the idea of working hard off the ball.
The then 40-year-old was completely confident in his philosophy, revealing his innovative ideas to a country unprepared for this revelation and earning him the moniker of "football professor."
In short, that moment sums up Rangnick's career. The belief he has in his philosophy has never wavered, even in the face of criticism. His innovations inspired many of the current generation of coaches in Germany, undoubtedly making him one of the most influential characters in German football.
A roaming coach
Rangnick never played professionally, but gathered coaching experience across the country. First at youth level in Stuttgart, then he led lowly Ulm to an unexpected rise up the divisions. Spells at Stuttgart, Hannover, Schalke and Hoffenheim followed, with Rangnick guiding the latter to the Bundesliga. His departure in 2011 was messy. A breakdown in trust between himself and Hoffenheim's main financial backer, Dietmar Hopp, proved too much for a man not known for his ability to compromise.
Rangnick rejoined Schalke and guided the team to German Cup glory and a Champions League semifinal. Seven months later, though, he left due to burnout.
An intense man whose playing philosophy is based around physical and mental intensity, the break was a reminder of how draining the job can be. Rangnick's search for control, even in the chaos, is reflected in his character. The qualified teacher is meticulous but also steadfast in his approach. It is always clear that he is the man in charge.
In a 2017 interview with DW, he said: "We know from the Hoffenheim experience that now that things are working, somebody like myself is needed to ensure that the things that affect the atmosphere around the club don't change."
Rangnick's enjoyed success with Schalke, but his spell in Gelsenkirchen ended in burnout
Perhaps that is why he is reportedly in line to take the sporting director and the head coaching jobs at AC Milan.
A man in control
Throughout his career Rangnick has always worked closely with Helmut Gross, a great football mind who became his long-term adviser. Together, the pair strove for a plan to control all aspects of the game, one that left no possible outcome unexplored.
It is perhaps worth noting that along with Valeriy Lobanovskyi and Ernst Happel, the former legendary Italy and AC Milan coach Arrigo Sacchi also had a strong impact on the pair.
After working on that style of play as sporting director at RB Salzburg, Rangnick started to look to perfect it later at RB Leipzig. There, he kept swapping between the sporting director and head coaching jobs before finally moving upstairs when Julian Nagelsmann arrived. Most recently he has been working as Head of Sport and Development Soccer for Red, with a suggestion in the job title that he is now in complete control of the football philosophy across the Red Bull family.
There's no denying Rangnick's influence, at both the clubs he has worked at and German football generally, but it is also worth noting it has been aided by circumstance. His work at Hoffenheim coincided with the club's desire to push innovation, and at Hoffenheim and RB Leipzig he benefited from extensive financial support, from SAP and Red Bull respectively. His ideas have never lacked the support needed to put them into action.
Rangnick is innovative, bold and is constantly looking for ways to give his team an edge. He has even been known to impose rules on which cars players were allowed to drive based on their age. He has developed ways for his players to recover during games and consistently looked to recruit, socially educate and develop players that suit his playing style.
His approach is also extremely demanding on players, both physically and mentally, but it also involves a degree of "error culture," meaning that he is prepared to accept some mistakes as part of the development process.
Rangnick is not an easy character to work with, but his ideas can make all the difference.