We've been conceding over 40 goals a season since 2010, prior to that it was mostly under 30 under Benitez. I don't think we can blame Klopp for this yet. We've had defensive woes for 6 years now and I think the root of the problem lies in either the midfield failing to protect the backline or hold the ball when the backline is regrouping.

I don't know, but I find it odd that the season we lost Alonso, we suddenly concede over 40. Did he gel the midfield together? Was he the engine of that midfield? Either case, we need someone like that there, solidify the midfield so that it protects the backline. Right now our midfield falls apart too easily, it's not solid or a silly mistake exposes our whole backline.

The two seasons Klopp won the league with Dortmund, they conceded under 26 goals and then the following 2 seasons they conceded a shit load. Maybe looking into those out transfers might lie the root of the problem and the key in fixing our defence.

I don't know, I'm only speculating, my only experience with Football is Sunday League and Football Manager.