Arsene Wenger says Arsenal's 12-game home winning streak is a result of their improved ability to handle counter-attacks -- but warned that ability will be seriously tested when Jose Mourinho's Manchester United visit the Emirates Stadium on Saturday.
Arsenal are already on their best Premier League run at home since moving to the Emirates in 2006, and a 13th straight win would match their streak from 2005 at Highbury.
Wenger says the streak is partly due to the switch to a back-three formation, which has made the side less vulnerable to quick counter-attacks.
"It's all linked a little bit with confidence, and the fact that we have been more stable defensively," Wenger said of the 12-game streak.
"We are a team that place many players in front of the ball when we attack, so we are sometimes vulnerable on counter-attacks. And on that front, maybe the fact that we play with three centre-backs helps a little bit to be caught less on the counter-attack."
Arsenal have kept seven clean sheets at home this season in all competitions, and the back three of Nacho Monreal, Laurent Koscielny and Shkodran Mustafi have yet to concede a goal in the six games they have started together.
However, they could face a stern test on Saturday. While Arsenal will be without leading scorer Alexandre Lacazette, Mourinho has Romelu Lukaku, Zlatan Ibrahimovic, Marcus Rashford and Anthony Martial all available.
"They have a lot of power up front," Wenger said. "Every player has power. Lukaku, now Ibrahimovic is back -- you cannot say that these guys lack power. Rashford, Martial ... they all have power. So our defensive performance will certainly be important, when we don't have the ball, to be well organised against them.
"They are very strong at [counter-attacks], and we have to be well organised for that."