Sergio Aguero and Manchester City were not their old selves at Newcastle.

The next week could be pivotal for the two teams at the top and Jürgen Klopp’s side are still enjoying the view from the summit

February is the cruellest month. Or at least, it often feels that way when it comes to separating out the moving parts at the top of the Premier League.

Last week, a full round of fixtures under the evening lights brought fresh contortions to what is an increasingly gripping title race. This has become a great deal more than just a straight dash to the line, broadening out into a piece of theatre that touches on managerial legacy, red-shirted will to power and elements of tactical compromise in a Manchester City team that appeared close to unstoppable a couple of months ago.

On Tuesday, City turned up at St James’ Park and performed like a group of movie-set stunt doubles running through some Manchester City-style motions for lighting and camera angles as a prelude to an actual Manchester City Premier League performance.

That limp 2-1 defeat was followed by Liverpool’s fretful point at home to Leicester on Wednesday, a game the league leaders might easily have won, but also saw the team’s muscular defensive heart in uncharacteristically brittle mood.

With their lead extended to five points Liverpool would probably have to lose at least twice between now and mid-May to miss out on the title. Their outstanding recent record against the league’s mid-table filler suggests this is a distant prospect. The draw with Leicester was the first time Liverpool have dropped points against a team outside the top six since April.

These are interesting times, though. The shift in early January into late midwinter has become a kind of division bell for the title race in recent seasons. It has been five years now since the last real umbrella-gnawing, down-to-the-wire finish. Since then, the decisive kick away from the pack has tended to arrive a little earlier, as fixtures pile up, injuries begin to bite or heal, and the midwinter-slog works its way into the bones.

This time last year Manchester United lost to Tottenham and Newcastle as January melted into February, while ahead of them City won five out of six and turned what was already a title procession into a hand-waving title trot-past in full ceremonial gold-leaf carriage.

The year before Tottenham dropped seven points while Chelsea just kept on storming on through as January melted into February. The season before that it was around the same time that Leicester began to find an unanswerable rhythm. With this in mind we are now entering what could be a key 10 days. Starting with Arsenal at homeon Sunday, Manchester City have three tough-to-middling league games in a week, with Everton away on Wednesday, and Chelsea’s mannered and fretful Sarriball all-sorts at home next Sunday.

Over the same period Liverpool play twice: West Ham away on Monday night, and then Bournemouth at home on Saturday. After which they have a two-week break in the league before trips to Old Trafford and Goodison at the start of March. Drop points now and those two fixtures start to look ominous, both of them against opponents who will be focused with a murderous eye on ripping a hole in that red-shirted pre-title triumphalism.

Perhaps with this in mind Pep Guardiola, so used to storming away as a title frontrunner, has even made his first few rather gauche attempts at a little cross-Lancashire mental disintegration. “All the teams who want to win the title have to feel the pressure, but you have to handle it,” Guardiola hammed in his Tuesday press conference. “I don’t know what they will think. I’m not in the locker room.”

While it seems unlikely Jürgen Klopp will find himself reduced to a state of quivering, tear-snorting Kevin Keegan-style meltdown at the force of these gentle little snipes, the timing of it is at least spot-on. For the teams at the top, this is the winter red zone. Best of all, this is a title two-hander that will come down to more than simply injury lists, luck and the form of key players. At stake for Guardiola and Klopp is something more, a systems-clash, a battle between pragmatism and perfectionism.

If Liverpool have an advantage this season it is that Klopp has been able to change his team’s rhythms, to play another way, to find other gears below the most extreme expression of his own gegenpressing, high-velocity attacking style.

Through the first half of the season Liverpool found a low‑corrosion way to win. The formula was clear. With the defence strengthened Liverpool knew they would rarely concede. At the other end the movement and craft of Mohamed Salah is usually too much for most defences.

From week to week, and the odd blip aside – we remember Klopp sprinting across the pitch at home to Everton like a man being chased by rabid huskies – they won with strength in reserve.

What is fascinating is the way the past few weeks, as muscles have tightened, have seen a return to the Liverpool of last season, or at least to a less controlled style. Every goal since Boxing Day has come from the front three. Clean sheets and controlled 1-0s have been replaced by a slightly wilder approach to winning. This is a team fighting not just its rivals at the top of the league but a weight of history, a shared emotional longing.

The battle for Liverpool from here might be to drop the throttle a little, to get back as far as possible to the calm, methodical pragmatism of the first half of the season even through the chills of a title-chasing February.

Whereas for City and Guardiola it is the refusal to change, the insistence on simply playing the same way, running though the same distinct registers that has made their title chase so engrossing. Guardiola teams don’t drop the throttle, don’t win in other ways. They improve by becoming more themselves, become more efficient and nuanced. Even in defeat, as at Newcastle, it is that same recognisable Pep-ball.

Hence this strange current run, whereby either the system clicks, the parts fall into place and City swipe opponents aside; or those rhythms can be disrupted, leaving the parts of the machine still running through the same patterns like a broken circuit board.

There are some who might say Pep hasn’t managed 99 Premier League games as City manager, but has instead managed the same game 99 times. This is both incorrect and beside the point. City have more ways of playing than simply classic short passing Pep‑ball, as did Barcelona and Bayern Munich before them. But there is something to be said for winning if not ugly, then without being forced to reach the higher registers, as Liverpool have done this season.

Guardiola’s ability to make his own very distinct kind of systems‑football work even in the mud and blood of a race to the line in Europe’s noisiest league will be key to what happens from here.