It wasn’t that long ago when Arsenal fans endured the years of Sebastien Squillaci, Johan Djourou, Philippe Senderos, and Mikael Silvestre manned the club’s central defense. While the Gunners have been widely known for their attractive, slick passing style of play since the arrival of Arsene Wenger 20 years ago, the team’s defensive record has been a bit shaky over the last decade or so.

Arsenal went six consecutive seasons from 2006/07 to 2011/12 with allowing the most goals out of the top four clubs in the Premier League standings. Although the Gunners have improved in defense since 2012, the current back four of Nacho Monreal, Laurent Koscielny, Shkodran Mustafi, and Hector Bellerin is without a doubt the north London team’s best defense since the mighty club went an entire season undefeated in 2003/04.

At the core of this defense, center back duo Koscielny and Mustafi are acting like a brick wall. Though they have only played six matches together since Mustafi’s £35 million move from Valencia in August, the pair have been impressive once joining forces. The Gunners have picked up five victories in these six games, and the tandem have only allowed one goal from open play during this stretch (against Paris Saint-Germain).

Arsenal’s crosstown rivals, Tottenham Hotspur, have a very daunting defense as well. In fact, many believe that their duo of Toby Alderweireld and Jan Vertonghen are the supreme center back pair in the Premier League. There is no doubting that the Spurs defenders are extremely talented; however, the new Arsenal defense of Koscielny and Mustafi may just be ready to take over as the league’s top twosome.

The Arsenal defenders didn’t exactly hit the ground running, however. Communication between the pair was visibly lacking in Mustafi’s first two matches with his new club. Southampton worried the Gunners at multiple times during the match, and the Gunners escaped with a 2-1 victory. The following match, a 1-1 draw against Paris Saint-Germain, was also a bit shaky for the newly paired center backs.

Striker Edinson Cavani put the Parians in front inside the first minute of the match. Nonetheless, Arsenal have rattled off five consecutive victories since that night in Paris, four of which Koscielny and Mustafi took part in. The defensive pair have also recorded three straight clean sheets as well, including a 3-0 drumming of another rival, Chelsea, on September 24th.

The achilles heal for the Gunners over the last decade or so has been in defense. Goalkeeper Petr Cech was a superior addition to the club last summer, and the emergence of Hector Bellerin has given this club a different dimension along the right flank, but the addition of Mustafi to go along with the world-class Koscielny in central defense could very well be what puts this Arsenal team over the top in their quest for their first Premier League title since 2004.