Arsenal, under Arsene Wenger, have never been known for their defensive prowess. If anything, the lack of defensive discipline has caused the Gunners many a game over the years.
However, recent performances have shown a defensive stolidity to the Gunners, with Steve Bould credited with bringing that backbone that Arsenal have needed so badly.
Per Mertesacker, who was again impressive against West Ham in his side's 3-1 win, where Olivier Giroud, Theo Walcott and Santi Cazorla scored, believes the Gunners' defense is starting to win them games.
Arsenal were under constant threat from Andy Carroll in the entire 90 minutes, but apart from a few hiccups, the central defenders and indeed the full backs defended admirably, to keep West Ham down to a solitary goal.
"We could feel in the air it was going to be a tough game," Mertesacker said. "We had to fight a lot, especially in the second half when the crowd supported West Ham they had a good advantage.
"But we came back into the game on the counter-attack and afterwards we played well, especially defensively. We won more and more headers which was vital.
"It (our defending) can be the difference, it is crucial for us that the defence is winning more games. We just try to keep that in our mind the whole year."
Arsenal started the season by keeping three straight clean sheets, but were criticized in the last couple of games for conceding from set-pieces. However, in the game against West Ham, a Sam Allardyce team, which are always dangerous from dead ball situations, the Arsenal side looked a lot more assured.
The Hammers scored through Mohamed Diame's brilliant finish, although the defending for the goal was a bit suspect. However, Giroud's fine finish made it 1-1, before Walcott came on in the second half and scored a brilliant winner. A perfect night was capped off by Cazorla's sublime long-range strike.
"What can you do about their goal? Sometimes that happens," Mertesacker added. "We have not conceded a lot of goals during games this year and most have been from set-pieces. We just need to keep concentrating on our defensive level.
"We needed to win to bounce back after the defeat against Chelsea. It's always good to win in front of an international break. We have good confidence and showed that especially when it was tough in the second half.
"West Ham had a few chances but we didn't let ourselves down. We kept our chins up and we have unbelievable quality on the bench which made the difference."