In all of the appreciation of Manchester City's free-scoring title challenge, Arsenal's best quality tends to get overlooked.
Arsenal have the second-best defensive record in the Premier League, conceding only 21 goals in 24 games. Their record at home is even more remarkable, conceding just six goals in 12 games. It is why Arsenal, like City and Chelsea, are in the title hunt.
Their worst defeat of the season remains a huge blot on the landscape, as they shipped six goals at Manchester City, which has meant they are second to Chelsea in goals conceded. But generally their defensive record has been superb because of a settled back four in front of keeper Wojciech Szczesny.
For my money, Szczesny has been the best keeper in the Premier League this season.
Who are the other contenders? Joe Hart. No. He is returning to form though. Simon Mignolet has had a drop in form. David de Gea has dropped the odd clanger. Petr Cech has been the best for a decade, but Szczesny and a new generation of keepers are pushing him this season.
Honourably, in an interview I did with him earlier this season, Szczesny held up Mignolet as being the best keeper in the Premier League last season.
This time around, Szczesny has learned from the mistakes of the last campaign, grown up and matured, and become not just a better keeper but a more rounded player. He is respectful yet confident. Szczesny once again made a big save at the right time, denying Crystal Palace on Sunday when the score was still 1-0. The big thing for Arsenal is that they now have a confidence at the back. The two centre-halves are rock solid. Per Mertesacker was outstanding against Palace. He reads the game well and knows when to step in and make challenges. He commands the air. Alongside him, Laurent Koscielny is smaller and more mobile but combative, and they have formed a terrific understanding.
Bacary Sagna is the mainstay at right-back. How on earth they have not tied him down to a new contract is a mystery. Sagna's level of performance this season has been as consistent as it has been impressive. Getting forward well, defending even better and solid.
At left-back, there's a battle going on between Nacho Monreal and Kieran Gibbs. Personally, I prefer Gibbs as he can attack and defend, has more pace and has performed better this season than Monreal. But it's a great contest.
Basically, it gives Arsenal the base from which they can go and win the game. The City thrashing will be held up to highlight the weaknesses, but Koscielny went off injured early. They lost at Old Trafford when Mertesacker was missing. Both were crucial.
Arsenal have settled on the 4-2-3-1 formation, and the solid back four means that whoever plays in the two deep midfield spots has confidence in the defence behind them. Mikel Arteta is a must, for me, but Alex Oxlade-Chamberlain has made a case to play alongside him.
They have a daunting run of four tough games in 11 days -- Liverpool away in the league, at home in the cup, Manchester United and Bayern Munich -- which will go a long way to defining their season.
But one thing is for sure: Arsenal now have a confidence and platform in their defence that should give them a belief that they can frustrate and defend against top opponents. And then go and find the goals at the other end, knowing that they can keep clean sheets.
The next couple of weeks will tell us a lot about Arsenal. But the past six weeks have proved they have a defence to tackle the challenges ahead.