How Jürgen Klopp worked wonders at Dortmund

Jürgen Klopp announced his decision to step down as Borussia Dortmund coach on 15 April 2015; exactly one year on it will be the morning after the second leg of his Liverpool team meeting his former club in the UEFA Europa League quarter-finals.

In seven years at Dortmund, the former Mainz coach led them to two Bundesliga titles, including the 2011/12 domestic double, and then a UEFA Champions League final. It was that record that persuaded Liverpool to appoint the charismatic 48-year-old in October 2015.

On leaving Dortmund, with three years still left on his contract, Klopp declared: "I have always said that the moment I feel I am no longer the perfect coach for this extraordinary club, I would say so. In the past days and weeks, I was not sure whether I was not the perfect coach anymore, but I couldn't say that I was either, so I saw it as my duty to inform [sporting director] Michael [Zorc] and 'Aki' [Dortmund chief executive Hans-Joachim Watzke].

He added: "I have nothing up my sleeve, but I also do not intend to take a sabbatical." Within six months Klopp was sat on the Anfield bench, and on 7 and 14 April will be facing Dortmund in a truly evocative tie.

Born in Stuttgart, Klopp came to Dortmund in summer of 2008 following a seven-year spell at Mainz, where he had spent his entire playing career. Together with Watzke and Zorc, he took over a side that had just finished 13th in the league and built a new team. They won two Bundesliga titles and a German Cup, and reached the 2013 UEFA Champions League final, losing to FC Bayern München.

Under Klopp, Dortmund put faith in emerging talents like Mario Götze and Mats Hummels and did great work in the transfer market, the likes of Shinji Kagawa and Robert Lewandowski exemplifying a knack for spotting diamonds in the rough.

Klopp's Dortmund were immensely energetic, pressing relentlessly and breaking at speed – a style which perhaps reached its peak in the 2012 German Cup final, when Dortmund overwhelmed Bayern 5-2 in Berlin. "Klopp was my best transfer as general manager," Zorc once said.

After Dortmund won a second successive Bundesliga title in 2012, Klopp said: "What is happening here is just crazy. If there was ever a side that deserved to be champions, then that's us. We have not lost for 26 games in a row – that's insane." National team boss Joachim Löw agreed. "Klopp has done outstanding work at BVB," he said.

However, things came unstuck a little this season, with Klopp's decision to stand down mirroring his experience at Mainz, where he quit after failing to win promotion back to the Bundesliga in 2007/08. "I am a better coach than I was in 2012," Klopp said in December, when his team was bottom of the league. "Unfortunately, this is not being reflected in the table."

Still, Klopp's final season did earn Dortmund a UEFA Europa League place, before he took his irrepressible enthusiasm to Liverpool. Having already led them to within a penalty shoot-out of League Cup victory, then negotiated Manchester United to set up the BVB tie, Klopp is ready to be the centre of attention once again.