Arsène Wenger has reverted to quips, his tried and trusted defence mechanism and a sure sign that he wants to diffuse the hostile line of inquiry. The Arsenal manager gave his latest offering on Friday, on the eve of the Premier League visit to Liverpool, when it was put to him that his team had tended to fall apart in February. "I must say that some people are very patient with us because they expect us to fall apart since August," he replied.

Arsenal have previous for hitting the buffers at around this time of the year, although not over the past two seasons, when it has been the start that has been the problem. Either way, the perception has taken root: Arsenal do not and cannot stay the course. The charge has been levelled at Wenger with wearying frequency this season and it has sometimes seemed as though people have been waiting for Arsenal to slump. But they remain at the top of the table. Might they yet go all the way?

1 Defensive stability

When Wenger was asked about the key difference between this season and those of the recent past, he plumped immediately for the solid foundations that he has at the back. "The main difference is there," he said. "We could always score goals, we could always master the domination of the game. If you look purely at the numbers, our defensive record is much more stable. It is vitally important, especially going into the big games."

Only Chelsea have conceded fewer league goals this season but the most eye-catching statistic involves Arsenal's in-form central defensive partnership of Per Mertesacker and Laurent Koscielny, whose contrasting styles have come to dovetail so well. Arsenal have not lost a league fixture that the pair have both completed since 22 January 2012.

Arsenal have benefited from their consistent presence – the club captain, Thomas Vermaelen, has been pushed to the fringes – while Steve Bould, the assistant manager, has had an influence with his work on the finer defensive details in training. The rest of the unit have also grown, with the goalkeeper Wojciech Szczesny, in particular, enjoying an excellent season.

2 Mesut Özil

The Germany attacking midfielder is famed for his timing – former coaches speak admiringly of the sweet sound that his connection with the ball makes – and it was right on so many levels when he joined Arsenal on the final day of the summer transfer window. The club's support, not to mention the players, had been desperate to see a marquee addition and, at a stroke, all of the anxiety could turn to excitement.

Finally, Wenger had spent big – a club record £42.5m – and Özil, a card-carrying Real Madrid superstar, brought a lift, particularly with his early performances. He was wonderful against Napoli in early October. Overall, he has not been Arsenal's star man – he has arguably not been in their top five – and Wenger would certainly like to see him score more goals. But he has fired the collective belief and there will be more to come from him. Arsenal hope that it is during the run-in.

3 Olivier Giroud's strength

There has been plenty of muttering about what Arsenal might do if Giroud, below, were to be injured, especially after the failure to sign reinforcements up front last summer and again in January. The France centre-forward has sometimes been Wenger's only option to lead the line, because of injuries elsewhere, and he has shouldered a heavy physical burden, having started in virtually every Premier League and Champions League game.

But perhaps it is time to recognise how he has thrived on the responsibility and back him to maintain his remarkable levels of stamina. He is Arsenal's top scorer with 14 goals in all competitions and he is on course to better his return of 17 from his debut season at the club, and so continue a trend from his career. Giroud previously spent two seasons at Montpellier and Tours and his second season at each club was markedly better than the first. At Montpellier, his goal tally jumped from 13 to 21; at Tours, from nine to 21. It has not merely been the numbers this season. Giroud's muscular hold-up work has brought balance to the team.

4 Continuity and momentum

It might sound like the most basic of requirements and hardly be cause for acclaim but the club's retention of their players last summer, after the traumatic departures during the previous two close-seasons, represented something to build on.

Commitment to the cause has underpinned the encouraging results and if Wenger's, as yet, unsigned new contract has been a sideshow – his current terms expire in June – there has long been the confidence behind the scenes that he will renew.

The recently announced £30m-a-season kit sponsorship with Puma has added the sense of upward trajectory while Mertesacker and Tomas Rosicky are ready to sign new deals.

As for Bacary Sagna who, like Rosicky, is out of contract in the summer, Wenger says that the club is "ready to give him more than one year because he is a defender". The 30-year-old, though, continues to keep his options open. "We are not close at the moment," Wenger added.

5 Nobody is invincible

Wenger said as much, amid the general clamour to anoint Manchester City as the champions-elect. City's attacking football has been beautiful to watch this season and yet they were outmanoeuvred and beaten by Chelsea on Monday to reinforce Wenger's point. Teams are cutting each other's throats. To quote the famous commentary line: It's up for grabs now.