Der Klassiker is the biggest match in the Bundesliga. Bayern Munich are one of the grand clubs of Europe, rattling off eight straight Bundesliga titles while Borussia Dortmund are the club usually trying to track them down. When the pair face off this Saturday (12:30 p.m. ET, ABC/ESPN+), there's a lot at stake.

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It had all looked as if Bayern were running away with their ninth consecutive title until mid-February. But then, in two games, they dropped five points against Arminia Bielefeld and Eintracht Frankfurt.

Dortmund could help topple them from the top of the table with a win, but if they pull it off, another club will benefit as RB Leipzig are two points behind Bayern and ready to pounce. Unfortunately for BVB and their passionate support, Dortmund are in fifth, 13 points off the top after a turbulent season which has seen coach Lucien Favre leave in December and Edin Terzic take over on an interim basis.

In other words, expect fireworks.

BVB have some of the most exciting young players in football, Erling Haaland, Jadon Sancho and Giovanni Reyna amongst others, but Bayern Munich still have the bulk of their treble-winning contingent from last season: including Robert Lewandowski, Thomas Muller, Manuel Neuer, Serge Gnabry, David Alaba, Alphonso Davies -- and Joshua Kimmich.

Bayern have a habit of hoovering up the Bundesliga's best talent (Leon Goretzka, Gnabry, Niklas Sule) from their immediate rivals and have even plundered BVB in the past for the likes of Lewandowski, Mats Hummels (who's since gone back to Dortmund) and Mario Gotze. Like we said, fireworks.

Last season's meeting in June in Dortmund was as tense as ever, even without fans. Borussia Dortmund were on a six-game winning streak, and four points behind Bayern Munich, with seven matches left in the 2019-20 season. Dortmund's home, the Westfalenstadion was empty. It had been a tense affair -- neither Haaland nor Lewandowski had managed to get on the scoresheet. Dortmund were matching Bayern in most areas, but still the game needed the breakthrough.

After 43 minutes on that evening, some neat interplay saw the ball at Kimmich's feet. Bayern's defensive midfielder took a light touch and another to set himself. It all looked a little scattered -- they'd nearly lost the ball to Haaland a couple of touches back, only for Kimmich to win it -- but 20 yards out, Kimmich knew exactly what he had planned.

"I always try to find the solution before I receive the ball," he tells ESPN. "Afterwards, I have to control it and to pass it. But when you know before where you want to play then all the things went faster."

He'd done his research and knew Dortmund goalkeeper Roman Burki was going to be a step or two off his line.

"I had to try something special -- Maybe it was a surprise for the goalkeeper," Kimmich says.

Without looking up, Kimmich floated this most delightful of delicate chips over Burki, and despite the Swiss goalkeeper getting a hand on it, the ball fell into the net. It proved to be the winning goal, and Bayern stretched their lead atop the Bundesliga to what proved to be an unassailable seven points.

"It was a bit lucky," Kimmich says, laughing at the memory.

Bayern would push on from there and would win a remarkable six titles -- Bundesliga, DFB Pokal-Cup, Champions League, UEFA Super Cup, German Super Cup and the FIFA Club World Cup. At the centre of it all was Kimmich.

He lacks the name recognition and may never grace the cover of FIFA, but he's arguably the most important player in the Bayern team this season, in his own industrious way. He's good at just about everything. Out of all midfielders in the Bundesliga this season (minimum: 500 minutes played) he leads the standings for touches of the ball (per 90: 101.7), passes (77.7) , and sits second for xA (0.37 per 90). Though he's won everything in Germany, he and the club still want more.

"We conquered [last season] but now we have to focus on the titles which will come," Kimmich says. "It's nice to want these titles but in football, the future will come, and you have to repeat and confirm."

This unwavering focus is why he's called the "mentality monster" by his manager Hansi Flick. Kimmich is now one of the world's best players, but rewind six years, and Bayern's interest in Kimmich was so bewildering to the then 19-year-old he asked the club why they wanted to sign him.

"I thought they could sign every midfielder, or every player in the world. Why would they want me?" he pondered.

KIMMICH REMEMBERS HIS FIRST MEETINGS WITH PEP GUARDIOLA, then-manager of Bayern, after the club announced his signing from Leipzig on Jan. 2, 2015.

"The first conversation was this -- I asked them why they wanted to sign me, and what they see in me. He showed me everything on the tactical map. It was amazing for me -- he showed me some positions I could play, that I didn't know I could play. I was like... woah... okay. When I worked with him more than just one hour, he showed me a lot. It was an amazing start."

Unbeknownst to Kimmich, Guardiola had been in the stands, enthralled, when the midfielder lined up for RB Leipzig against 1860 Munich on August 10, 2014.

"[Guardiola] called me straight away and said: 'super player, we must take care of this immediately,'" Bayern chairman Karl-Heinz Rummenigge said in 2015.

It mirrored the way Leipzig had scouted Kimmich at his previous club, VfB Stuttgart. Alexander Zorninger, then the Leipzig manager, was on a scouting mission at a Stuttgart U19 match, watching another player, but it was Kimmich who caught his eye -- the intensity, the running between the lines and how the ball gravitated towards him. Those at Leipzig remember the conversations: they hoped to keep him, having signed him on a two-year loan from Stuttgart.

But then came Bayern and Guardiola -- no player in Germany could ignore those advances. The young Kimmich was ambitious -- he wanted to play among older players when he left Stuttgart for Leipzig. But he arrived injured and it took months for him to settle. Senior players would see him work, hungry to finally get out there.

"Us guys thought what's that kid doing here? Well: He put in extra shifts. He was the first at the ground, working out in the weight room before training and then staying on the pitch after training," Daniel Frahn, RB Leipzig captain at the time, tells ESPN.

Finally, in a match at third division leaders Heidenheim in October 2013, Kimmich got his chance and never looked. Though it was eight years ago, that performance has stayed with those who witnessed it.

"He already had a great attitude and mentality back then," Heidenheim coach Frank Schmidt tells ESPN. "And today, he's nearly a complete player."

Zorninger also lauded Kimmich's winning mentality.

"He wants to win games no matter what," Zorninger tells ESPN. "That is one of his great skills. And he has a much bigger influence to control the match from holding midfield than from right-back. He's not only a great chaser of balls but also with his constant pressure on the ball puts the opponent into awkward positions and thus makes it easier for his teammates to win the ball."

Pressure. A chaser. You see it in Kimmich in virtually every game: Look at the Champions League clash with Lazio on Feb. 23 when Kimmich pressured defender Mateo Musacchio into playing a poor pass directly to Lewandowski to score their first. Then there was Kimmich's role in Bayern's winner at Bayer Leverkusen in December -- Kimmich hustled the Bayer defence into giving up the ball to allow Lewandowski to score an injury-time winner.

Usually, others will get the headlines but to understand Bayern, Kimmich is the key. He sets the pace, he makes the runs and the game revolves around him. There are occasions when he wants it too much, when he takes on yet another opponent and loses the ball. Watch him closely in the moments before he loses the ball.

"He has this move where he falls into the opponent when losing the ball in midfield, and he actually gets a free kick. It shows the cleverness," Daniel Frahn, Leipzig club captain from 2013-15, tells ESPN.

For as much as he's shown his ambition and vision, he's never been afraid to pick up ideas from his peers in order to improve his game -- he's a bit of a footballing magpie, and those early training sessions at Bayern Munich were important formative experiences for Kimmich.

"[He] helped me a lot, because we played the same position," Kimmich says of Xabi Alonso, his former teammate and World Cup winning midfielder from Spain.

"He always tried to tell me that I had to control with the foot which is in front to control the ball. To cover the pitch -- he helped me a lot with the orientation on the pitch and to know where my teammates are."

Kimmich played alongside some of his heroes -- Alonso, Arturo Vidal, Thiago -- and followed in the footsteps of legendary Bayern midfielder Bastian Schweinsteiger. Yet even in a squad full of world-class talent, Kimmich made 36 appearances for Bayern in his debut campaign in 2015-16.

"I played that season in nearly every position," Kimmich says. "I played the most games as a central defender, I played right back, I played central midfielder. I also played one time as a winger in one half in Zagreb. It was an amazing year for me, as I could learn nearly every position.

"This step was a really big step for me but it was the most important step in my career. Fortunately, I did it and now I'm still at Bayern Munich. I hope I have made them proud."

This was the first time a second division player had made a real impact at Bayern since Roland Wohlfarth was brought in from MSV Duisburg in 1983. To the outside looking in, this was a remarkable achievement for the 19-year-old Kimmich. He was 5-foot-9 and holding his own -- even at centre back. But from those who saw him at Leipzig, his rapid elevation was no surprise.

"He's the most ambitious player I have ever played with," Frahn says. "You couldn't talk to him after a lost training match. He was just shattered, thinking about why he lost that match. He wasn't really an 18-year-old. He was ahead of his age."

FAST FORWARD TO 2021. Kimmich is usually deployed as a marauding defensive midfielder, hovering, passing, sniping, intercepting, and driving with an unbelievable work ethic. He laughs when he is referred to as a "mentality monster" but he's unapologetic for his competitiveness.

"It's in me, since I was a child," Kimmich says. "I've always wanted to win every game. Not only in football, but in other things. But you learn it when you come to this club here."

Kimmich used to stew on Bayern's rare defeats, micro-analysing his own performances, but he has since learned to compartmentalise and develop an "off" switch after the final whistle. It also helps that he has family waiting at home; he and his girlfriend Lina Meyer are proud parents of two young children.

"It [fatherhood] didn't change the most important thing for me -- as it doesn't matter if I'm a father or not, I just want to enjoy the game. I just started playing football because it's fun for me, it's the best thing for me. But when I come home, I don't think that much about football as I did before.

"When my kids and girlfriend are there, I want to spend time with them and don't think all the time about football and what I did wrong. I think before the kids, this was different -- when I came home it was football, football, football all the time, every day. Now I have another balance in my life."

Kimmich has also channelled this energy into giving back, throwing his weight behind the charity initiative #wekickcorona, which started with him and his midfield partner Leon Goretzka each donating €500,000 to the cause. Those funds were then distributed to non-profit organisations needing the funds most -- they have helped foodbanks, the homeless, blood donation services and local hospitals. They now have 4,200 donors on board.

"It's a big thing we have -- it's special for us there are a lot of people who have donated their money -- they think these two guys will give it to people who need it. This is a special thing for us. Not only that there are some German Bundesliga players who want to help us -- but also the other guys. There are a lot of people and this makes us proud."

One of the finest moments in Bayern's remarkable 2019-20 season was that 8-2 win in the Champions League quarterfinals over Barcelona . They were 4-1 up at half time against Lionel Messi & Co. without breaking a sweat.

"We felt good at half time, when you take the lead 4-1 against Barcelona. It was simply amazing. We had to keep going, continue and had the chance to make a big result and we did it. The motivation was big -- it is a Champions League. You try to keep going, it doesn't matter if it's 1-0 or 4-1. For us it was important to perform well, and we wanted to show the other opponents we were there: FC Bayern Munich want to win the Champions League this year."

And that is the same this year. They are still trying to scratch the itch of having won all of those trophies without their fans there to see the feat. They want more silverware this year. He touches on their premature exit from the DFB-Pokal Cup -- you sense it's a wound he's keen to heal next season.

"The ambition is always to win everything here. It's really special in this club to have the opportunity to win everything... This is our big goal -- unfortunately the [German] cup is not there this year, but there is still the Bundesliga and the Champions League, and we try to win it."

The accolades will continue for Kimmich, too. He was named in FIFA's Best XI last term.

"It meant a lot for me to be in it -- for me as a kid, or a young guy it was amazing to see the guys in this team, the best guys in the world, and for me it's unbelievable to be one of them in this year. We won everything -- that's the most important thing for me, to be successful in this team -- but when you're also important for your team who are successful, this is the greatest you can reach."

But is not holding out for the top individual award any time soon. "I have to score more often to win the Ballon d'Or."

Kimmich was starting to get a little agitated as he had a team meeting waiting he could not be late for. They're planning for Borussia Dortmund and how to stop Haaland.

"As a team," he says of how they plan to nullify the Haaland threat. "Like always, as a team."

A win on Saturday will be another step forward for Bayern Munich to what would be their remarkable ninth straight Bundesliga title. Kimmich has been there at the heartbeat of six of them. But they want more.

"The hunger is special. We have a special mentality," he says. "We have a lot of guys who want to win everything, every single game. In training the guys want to win. This is special when you're in a club and we won the Champions League, the six titles, and we had a nice run in 2020 and we want to continue and repeat that. We want to be successful in the future and we will give everything for that."