There's no way I could write today without mentioning Barcelona's incredible performance. A 4-0 defeat in the first leg turned around with a 6-1 victory in the second.
One aspect of their performance that struck me today was their defending, especially their center backs. The whole Barca team parked themselves in PSG's half, and stayed there. This was due to both the work rate of the attacking players' as soon as the ball was lost, but also the decision-making by the 3 defenders of when to step out, when to delay, and when to foul.
One thing I appreciated more after a course with Frans Hoek was that when the ball is lost, the goalkeeper and backline need to step towards the ball to shrink space. Umtiti, Pique, and Mascherano did that masterfully today. The PSG attackers didn't have time to pick their heads up because as soon as they received a pass, a Barca player would be closing them down. In my opinion, this was a major factor in Barca's win today. Keeping the ball in PSG's half not only kept Barca relatively safe defensively, but allowed the likes of Neymar, Suarez, and Messi to play within 40 yards of the goal most of the game.
This will be a game I watch again with a clearer head, and one I'll be sending out to my center backs to study.