Borussia Dortmund have been back and forth from being the best and far from it, but lately they've become a top European force. They always challenge domestically, and on the European front, nobody wants to face them. They create top talent after top talent, but perhaps their biggest problem is failing to keep players in their Borussia Dortmund soccer jersey for long. The club regularly lose its top talent to rivals Bayern Munich, which simply has to stop if they're ever to close the gap on them. Another problem is their willingness to sell a player and allow them to return a few years later. A period of stability could indeed see the team become the best in Germany and possibly Europe.