once a team is behind 1-0, it has to risk its defense for more attacking. Well it's always been like that, but with modern tactics, training methods and overall team strength and stamina, this effect strikes even harder. That's why many matches between equal teams nowadays end 5-1 like Netherlands vs Spain, or 4-0 like Germany vs Argentina in 2010.
then additionally that was bad luck for Brazil. 3 goals in 4 minutes can happen, but doesn't have to. These 3 goals could as well have been missed chances.
That is a fair point. Also the Brazilians are missing two good players, and they have a lot more pressure on them in my opinion because of home advantage. And to top it all off, Germans are known for always being efficient - they have a tendency to score when they get the chance, while you constantly see players on most other teams miss many obvious chances.
They did not have to risk more in defense this early in the game. The last goal was made before the 30th minute. The tactics of the Brazilians weren't very good. I really dislike their coach.
You can not blame luck when your players do not work hard. It is the biggest stage, at least run around a bit, press and try to win the ball. An average team with good work rate can go far if the players are up for it, as Costa Rica showed.
They are going to concede more here.
The Germans are sparing them. They're playing at 70%.