The first is an example of our underrated defending in top games during Lucho.
Phase 1. Suarez loses the ball resulting in a turnover. Completely gifted the ball to Arsenal.
Phase 2. Arsenal get the ball to Sanchez (foto down).
Alves makes a move on Alexis, pretty quick. Both him and Rakitic press the ball carrier. Which is one of our most used tactics on the right wing. Problem is Alexis, being a top player, plays a brilliant 40m pass to Ramsay. But note the position of our players. It's very correct. Pairs are being formed while Alves and Rakitic press Sanchez. We see Suarez being in the middle, relatively close to Coquelin (who is not that great on the ball). Busi takes Ozil under marking (Ozil attacks space left by Alves' pressing), Pique is with Ramsay, Alba's keeping an eye on Chamberlain and Mascherano is off frame dueling with Giroud. That is a solid defensive set up imo, considering this Arsenal attack was a turnover by Suarez, and we had little time to react. Alexis puts us in trouble with a brilliant pass, but one which rarely comes through. So, in most cases, we solve this attack by forcing the opposing player (Sanchez here) to safe-pass to one of his teammates (Monreal or one of the CBs seems the safest passing options for Alexis).
Phase 3. Pass is great, Pique makes a slight mistake, losing the duel by watching Ramsay instead of the ball. Positioning is still OK imho.
Pique lost the duel with Ramsay, something which rarely happened in the game (Pique is usually solid in this type of duels). Here he makes a mistake by watching Ramsay more than the ball itself (the pass is great, but it's also high, a defender has time to settle for it). Ramsay plays a great backheel to Ozil, which has a bit of an advantage in front of Busi. He can cross into space marked with red on the photo. Alba is important here as well. You can see him watching if there is anyone coming on his flank, in order to know what to do. If Chamberlain is not there, Alba comes in and probably goes to close that bit of space Ramsay has.
Phase 4. Busi could have stopped the cross, which would've been immense.
Phase 5. Ozil passes the ball, not great, but still, Ramsay is in a position to get something from this play.
Here is why Mascherano is a great player. He is a player of action. He would anticipate the danger. He sees that we could be exposed here, and makes a move to stop Ramsay, although he initially marked Giroud in this play. He leaves his man, wich now had Pique next to him, and stops the only player that had a good position to score. Other CBs would have just stayed close to their man (Giroud).
This was very good defending from us. Normally, this attack is stopped at phase 1 or 2. Phase 1 would mean that Suarez is more careful with his passing and doesn't give the ball away. Phase 2 is that Alves and Rakitic pressure Sanchez into playing a safe ball and we regroup better. Phase 3 is that Pique usually wins his duels. Phase 4 is that we could try to block the pass.
We didn't manage to stop the attack in phase 1, 2 3 or even 4. It got to phase 5, but we still stopped it there. It is reassuring that we can also defend pretty well when the action of the opponent is goal-imminent. Mascherano is our best player at stoping attacks in later phases.
This is very good defending from us. We're not only very good at counters, but we're very good at blocking them.