Bayern were a bit naff in the year Klopp won his first title with Dortmund, which is the claim I made. I said they were good the year after, although obviously not as good as they were the year after again. They finished third in the league behind Bayer Leverkusen in 2010/11, and were turfed out of the CL in the first knockout round, changing manager partway through the season.
Klopp did well to win with Dortmund, but there's a bit of a myth surrounding it that makes out like he single-handedly put a stop to a period of Bayern dominance, which I think has come about because of how dominant Bayern have been since 2012/13. The facts are, however, that there were three different winners in Bundesliga in the four seasons prior to Klopp's first win, with Bayern in fact finishing 4th in one of those seasons and failing completely to qualify for the CL. They were a picture of inconsistency, which is demonstrated by the five managers they went through in that time. Heynckes got them going again in 2011/12, but Klopp's Dortmund proved themselves better over the course of the season, but in 2012/13 Klopp's Dortmund fell off a cliff and were nowhere near Bayern in any season again up until his departure.
None of this means Klopp didn't do a very good job, but history is slightly rewritten in his favour quite a lot.
He's done a good job at Liverpool too. Before his arrival they were firmly behind United, Chelsea, City, Arsenal and Spurs, and now they're very much in the mix at the top of that group. Time will tell if he can cement that place with some concrete success.
