Oh, and for what it's worth, this is probably a bit of a wet blanket, but Dortmund's defence is quite the story of mean reversion. See, for 3 out of 4 seasons before Klopp joined, they averaged 43 goals conceded. In 07/08, right before Klopp arrived, they had an awful season - an exceptionally bad season defensively you could say - and finished with 62 goals allowed. Here's the full list of before / afters:
03/04: 48
04/05: 44
05/06: 42
06/07: 43
07/08: 62 !!!
08/09: 37 << Klopp's first season... immediate improvement (against a shit base yeah, but also against the previous average of 43 in the 3 seasons prior to 07/08)
09/10: 43 << wait... so they didn't improve... damn?
10/11: 22 << WTF... champions, and a massive improvement... exception perhaps?
11/12: 25 << boom... maybe not, real deal, baby!
12/13: 42 << da faq!?
13/14: 38 << better, but still... 10/11 and 11/12 now look like exceptions
14/15: 43 << woah and woe
13/14 and 14/15 were seasons crippled by injuries though, but 12/13 is a bit odd. Didn't and don't follow Dortmund so I don't know what happened - I usually just find numbers and read some bones.
Now, on the other hand, the offensive side is a different story.
03/04: 59
04/05: 47
05/06: 45
06/07: 41
07/08: 50
08/09: 60 << Klopp's 1st season
09/10: 54
10/11: 67
11/12: 80
12/13: 81
13/14: 80
14/15: 47 << injuries
As you can see, sustained improvement from 08/09, even given the somewhat dull 09/10, and then consistency from 11/12 to 13/14. 14/15 was a hell season with injuries, and Klopp's departure came at the end of it of course.
03/04: 48
04/05: 44
05/06: 42
06/07: 43
07/08: 62 !!!
08/09: 37 << Klopp's first season... immediate improvement (against a shit base yeah, but also against the previous average of 43 in the 3 seasons prior to 07/08)
09/10: 43 << wait... so they didn't improve... damn?
10/11: 22 << WTF... champions, and a massive improvement... exception perhaps?
11/12: 25 << boom... maybe not, real deal, baby!
12/13: 42 << da faq!?
13/14: 38 << better, but still... 10/11 and 11/12 now look like exceptions
14/15: 43 << woah and woe
13/14 and 14/15 were seasons crippled by injuries though, but 12/13 is a bit odd. Didn't and don't follow Dortmund so I don't know what happened - I usually just find numbers and read some bones.
Now, on the other hand, the offensive side is a different story.
03/04: 59
04/05: 47
05/06: 45
06/07: 41
07/08: 50
08/09: 60 << Klopp's 1st season
09/10: 54
10/11: 67
11/12: 80
12/13: 81
13/14: 80
14/15: 47 << injuries
As you can see, sustained improvement from 08/09, even given the somewhat dull 09/10, and then consistency from 11/12 to 13/14. 14/15 was a hell season with injuries, and Klopp's departure came at the end of it of course.