The Dortmund team is consistently playing well. I would say their performance is stable due to their good match strategy. Not that they can dominate every match. However, their overall performance has been pretty consistent, and has earned points in almost every match. I can't remember the last time I saw a Dortmund team lose. And if this performance continues, there is no doubt that they will compete with Bayern Munich for the title. I will be happy if Dortmund can break Munich's dominance and win the title.
That took a while though, I know it is not something everyone wants to hear but Dortmund started terribly to this season. I guess that it was definitely just an issue for the short term and they got much better and right now they are playing much better, which is a good thing for them and definitely something I can see myself and agree with.
However, we are not guaranteed to never see that bad Dortmund ever again, they may go back to how they were at the start of the year and start to lose some points as well, it is not a sure thing. I hope that they won't and I hope that they would do a lot better in the long run but I do not know if they could or not.
They had this great momentum to break bayern munich record for winning the bundesliga consecutively since 2013 , everyone sick of it already and dortmund failed multiple times since then to steal the title , bayern simply too strong and consistent but this time there is some vulnerabilities in bayern munich.
Dortmund should take that advantage by breaking bayern mentality in the next meet in april 1st and not to losing points until then. Though job but now or never.