Unai Emery has brought new life to Arsenal.

The Gunners are undefeated in their last 19 matches.

Multiple performances have had supporters singing, “We’ve got our Arsenal back.”

There are many reasons that have led to the revival at the Emirates, and the 4-2 victory in the North London Derby showcased all of them.

Tactical flexibility

Unai Emery has used a variety of formations successfully this season.

Having a gameplan tailored to the opposition is a vastly different approach to the previous manager, who attempted to impose his will on the other team come hell or high water.

Earlier this season, Emery used a 4-2-3-1/4-3-3 with successful results. The Gunners have also come out in a 4-4-2 several times, utilising the partnership between Alexandre Lacazette and Pierre-Emerick Aubameyang.

This weekend he deployed a 5-2-3 system that proved wildly successful against Tottenham. The trio of centre-backs effectively neutralised Harry Kane. The attacking wingbacks were then free to venture forward. But what really made the system “click” was Emery’s tactical substitutions after the break.

Arsenal have very much been a second-half team so far this season. Several matches have seen them come out flat, only to come roaring back in the second half. This victory was the best second-half comeback yet.

Bringing on Ramsey and Lacazette brought more creativity and added hold-up play. The result was better control of the middle of the pitch, especially on the counter. Ramsey provided two assists, and Lacazette got what proved to be the match-winning goal.

Emery’s tactical flexibility, both in schemes and adjustments when things do not go as planned, are a major factor in Arsenal’s success this season, epitomised in the 4-2 victory in the North London Derby.

Never quitting

Arsenal falling behind and absolutely capitulating had become an all-too-common occurrence in the last days under Arsene Wenger.

No more is that the case.

This was first seen in the eventual defeat to Chelsea after the team came roaring back and really deserved a result in a fantastic game.

On Sunday, Arsenal’s newfound determination to not be defeated produced its best moment yet.

Down 1-2 at halftime due to a ludicrous penalty decision from the infamous Mike Dean, Arsenal looked very much like crumbling. But the second half was all red—just like North London.

Arsenal scored three unanswered goals in the second half to finish the match 4-2. A result like that was unthinkable seven months ago.

A fair criticism of Emery is that Arsenal would not have to be in these positions if the team started better.

Hopefully, the first halves will improve with time as the manager gets to know the Premier League better.

For now, these second-half comebacks are exceptionally entertaining and a breath of fresh air for fans who have seen the team collapse after falling behind far too many times.

A lot of this is down to intangibles like the next point…

Return of passion

Many critics of Arsenal over the last several years have stated a perceived lack of passion.

The current squad’s pride in the shirt is one thing that cannot be doubted.

The (almost) brawl on the touchline after Eric Dier’s equaliser was the first instance. The substitute players warming up were not going to sit idly by during his disrespectful celebration.

Interestingly, Matteo Guendouzi and Stephan Lichtsteiner—two Arsenal newcomers—were in the thick of it.

Lichtsteiner showed his passion for the club further in sprinting down the touchline to start the dog-pile on Lacazette after his goal, captured by club photographer Stuart MacFarlane.

https://twitter.com/Stuart_PhotoAFC/status/1069296316033961986

And then there is Lucas Torreira.

He has been incredibly valuable as a player in his debut season. However, up until Sunday it had been lacking a goal.

His desperation to get on the scoresheet has been evident the last few games, with an uptick in the amount of long-range strikes he attempts.

His first goal for Arsenal coming in a win in the club’s greatest derby led to boiled over emotions from the player, and an iconic moment.

Finally, not enough can be said about Matteo Guendouzi.

He has been exceptional after coming to the club with low expectations because of his age.

Throughout his debut season, he has worn his heart on his sleeve. It would appear as if he already has Arsenal coursing through his veins.

In addition to sticking it to Dele Alli, he also took time to celebrate with fans after the game—hanging his whole body out of his car window and celebrating into the night:

https://twitter.com/Arsenal/status/1069297409044488192

The pride in the shirt has returned, and the results are showing.