I am sure that Dortmund doesn't really play with a consistency, but at the same time that has something to do with changing the manager too. At the start of the season, they didn't had the proper manager and they did terrible, this season they fired him and got someone better and now they are doing better.
I wouldn't want to be harsh on Nuri Sahin, he is a good manager but he just didn't fit good with Dortmund and they just didn't had any chemistry so the results weren't coming at all. Kovac had a lot more chance to do a better job so he is doing a great job, and he is averaging better results so far as well. I guess that doesn't make him a better manager right away, but just a better fit with the Dortmund team at the moment.
Nuri Sahin was an experiment that failed. At a time when most top clubs in the German League are managed by young coaches, Borussia Dortmund brought him in after the glorious departure of Edin Terzic. To be truthful, he was not a good manager in the club. The club, which played in the UEFA Champions League finals, began to struggle and became highly inconsistent. It was because of the struggles at the beginning of the season that they fell below the Champions League position.
They are currently winning the game against Holstein Kiel and SC Freiburg is
playinglosing against
a draw with Eintracht Frankfurt. If the game ends this way, the Black and Yellows will make it to the biggest club competition in Europe. If that happens coach Niko Kovač will be highly celebrated for bringing the club out of the woods.