A cross from the right. Two defenders jump and can’t quite connect. Dejan Lovren, startled that the ball has got as far as the back post, realises too late that Arkadiusz Milik has stolen behind him; he cannot get to the forward in time. Time slows. Milik is in form; he has the best goals‑per‑minute ratio in Serie A this season. Eight yards out with just the goalkeeper to beat, it seems he must score the goal that will put Napoli through.

But Milik doesn’t score. He jabs without conviction. Alisson does everything he can, springing from his line, spreading himself towards the ball, which hits his body and cannons to safety. Liverpool have survived.

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In that moment, the narrative changed. Had Milik scored, the discussion now would have been of Liverpool’s poor away form in the Champions League (five games away from Anfield now without a win), of their remarkable profligacy in the second half against Napoli, and of their tendency still for defensive lapses at key moments.

Liverpool have let in only six goals in 16 games in the Premier League this season but an exit on Tuesday would have raised the question of whether they are one of those strange modern sides that cannot really defend but do not let in many goals, who control the ball so well that their opponents rarely attack, but then look vulnerable when they do.

But Liverpool, perhaps, are not one of those sides, or at least not in the way that Manchester City and Barcelona can be. For one thing, Alisson did make the save. To quibble, as some have, that Milik poked the ball straight at him misses the point: the goalkeeper did everything possible to make it difficult for Milik. That it did not then require some improbable reflexes or gymnastics to keep the ball out might detract from the spectacle but it does not detract from the quality of the goalkeeping.

Alisson is a better passer than either of his immediate predecessors, Loris Karius or Simon Mignolet, and has the great advantage of radiating calm, not panic. He also saves more shots. There seems an odd attitude to goalkeepers in that regard, as though making saves is somehow cheating, that the real game is not to concede chances. It is true that at a structural level teams are essentially seeking to control the distribution of chances, or at least to make those they do concede as difficult to take as possible. But equally a goalkeeper who saves shots is just as valuable as a striker who seizes chances. Coaches try to implement systems that control what moments are created, but it is then down to the ability and temperament of the players how those moments play out.

Similarly, Virgil van Dijk has had an extraordinary impact at Liverpool. This season the 27‑year‑old Dutchman has made more interceptions per game than any other central defender at a top-six side. On Tuesday, he had one of those games in which he just seemed always to be in the right place, a siren calling Napoli’s attacks on to his rocks. But Van Dijk’s impact has also been structural and the improvement in Liverpool’s defending remarkable: last season Liverpool played 24 league games without Van Dijk, conceding 1.17 goals per game; in the 14 in which he played they conceded 0.71 goals per game. This season, in which Van Dijk has played every game, they are conceding 0.38 goals per game.

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It is not, though, just about individuals. There has been a notable shift of approach. Liverpool have not pressed as hard of late, presumably to try to keep players fresher for the latter part of the season. This campaign Jürgen Klopp’s side are regaining possession in the final third 4.1 times per game, as opposed to 4.5 last. Opta’s more complex metrics paint a similar picture of Liverpool playing a more measured game. The average number of passes opponents make in sequences in the middle and defensive third, for instance, is up from 11.2 last season to 12.8 this, while opposition moves progress on average 11.9m this season as opposed to 10.9 last.

That has an impact on how Liverpool play as well. Last season their per game average of moves of 10 passes or more that ended in a shot was 3.39; this season it is 4.12. That has meant a readjustment and, without such intense pressing – “The best playmaker in the world,” as Klopp once called it – the midfield three of Jordan Henderson, James Milner and Georginio Wijnaldum can look a little staid. Mohamed Salah and Sadio Mané have both had to adjust to not having full-backs tearing past them at every opportunity.

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But the benefit has been that Liverpool have looked more defensively solid, and this approach is taking less of a toll on players. The way high-intensity sprints are recorded has changed from last season, so a direct comparison is not possible, but some indication of the changing demands is given by the fact that both Trent Alexander‑Arnold and Andrew Robertson are running around 3% less than in 2017-18.

If Liverpool are fresher come March, that could be significant to the outcome of the title race. Not only have they subtly changed the balance to adjust the sort of moments that occur, but sharper players should be better equipped to excel in those moments. The improved defence is part of a far greater picture.