Four unanswered goals separated Liverpool and Arsenal back in August but on the morning of Friday’s reverse fixture, a single point will separate them in the Premier League table. Which of those facts better reflects the gap in quality, if indeed such a gap exists?

Liverpool were superior in every department at Anfield four months ago. From Roberto Firmino’s opener to Daniel Sturridge’s coup de grâce, not forgetting Sadio Mané’s and Mohamed Salah’s goals in between, it was a consummate counter-attacking display of the type that Arsène Wenger’s teams once regularly rolled out.

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The idea that these were two evenly matched sides with similar expectations for the season ahead seemed farfetched that day, especially if you watched the footage of the third goal released by Liverpool’s in-house television channel.

The camera is fixed in Anfield’s Main Stand tunnel. A club employee, a policeman and a steward stand in the tunnel’s mouth facing the pitch. All three look suddenly excited, then a flash of red zips across the background of the shot. That’s Salah. Before you know it, he's out of shot again, continuing his sprint towards Arsenal's goal.

Four or five slower red and blue blurs follow him, then a few more arrive at a slower pace still, until eventually a jubilant Anfield erupts into a cheer. Only deflated Arsenal players are left in the background of the frame after that, clutching at their knees, sure of their defeat.

Wenger described that day as one of those which “hurts you for the rest of your life” this week. Even at that early stage of the season, after just three round of fixtures of a 38-game season, it seemed to indicate a gulf in class between his side and Liverpool, as well as the rest of the Premier League’s leading pack.

However, as we approach the halfway point of the season, 15 more rounds of fixtures later, the difference between these two teams is not so clear.

Just one point separates fourth-placed Liverpool from fifth-placed Arsenal in the current Premier League table. There was precisely the same margin between them in precisely the same positions on the final day of last season, when Jürgen Klopp’s side pipped Wenger’s to the one remaining Champions League place.

Liverpool deserved to edge it back then. Not only were they consistently in the top four for much of the season, they also beat Arsenal home and away. Yet the fact is just two points stand between these clubs over the course of almost one-and-a-half Premier League campaigns. It suggests they are evenly matched, despite recent head-to-head meetings.

It is not only the league tables which suggest that either could triumph at the Emirates on Friday. That much is obvious from their home and away records too. Only Pep Guardiola’s Manchester City, the runaway league leaders, have scored more goals in front of their own fans than Arsenal this season. Only City’s nearest challengers, Jose Mourinho’s Manchester United, have kept more clean sheets at home.

That latter record will be tested by one of the league’s most potent attacks, who are especially deadly when on the road. Liverpool’s 24 away goals is matched only by the imperious City. Klopp would be the first to admit that his side's defensive form away from home can improve – it is the top flight’s fourth-worst, in fact – but that is somewhat skewed by heavy defeats at the Etihad and Wembley. Liverpool have noticeably kept things tight at the back of late, allowing just four goals in their last nine games.

Overall, the picture is one of two similar teams with their own strengths and weaknesses that will either make or break them. With the benefit of hindsight, that result in August, emphatic though it was, seems less like clear proof of superiority and more like the kind of lop-sided scoreline that can happen when two similar sides whose styles revolve around counter-attacking meet.

Klopp’s men stole a march on Arsenal earlier this season, blitzing their penalty box in the opening quarter of an hour until finally, Firmino found an opener. From there, Arsenal offered nothing. Had Danny Welbeck converted when through one-on-one in the sixth minute though, it surely would not have ended in such a dominant Liverpool win.

Those are the fine margins on which these games between top Premier League teams are decided. To say so is a cliché, but one that feels especially relevant this season. As City streak away at the top, Arsenal, Liverpool and other members of the chasing pack are left to jostle for position, without much at all to choose between them.