sport news Liverpool formation switch by Jurgen Klopp worked in Rangers win trends now
Was it a 4-2-3-1? Was it 4-2-4? Trent Alexander-Arnold suggested afterwards it was actually your old-fashioned 4-4-2.
Whatever, it wasn't the usual 4-4-3 and it was precisely what Liverpool needed to lift the mood following an unimpressive start to the season.
Jurgen Klopp knew something had to change, system-wise, after his team were repeatedly picked apart by Brighton in that helter-skelter 3-3 draw on Saturday.
Liverpool returned to winning ways against Rangers after a difficult start to the season
Jurgen Klopp switched Liverpool's system from a 4-3-3 to more of a 4-2-3-1 or 4-2-4 and gained the rewards with a 2-0 win at Anfield
The German trusted his instincts, sacrificed a midfielder for an additional forward and saw his team dominate Rangers in a 2-0 Champions League win to get themselves back on track.
The Scottish side were clearly inferior and generally unadventurous but Liverpool's formation switch worked and Anfield went home happy.
The Reds enjoyed 64 per cent possession and carved out 23 shots, of which 10 were on target. Alexander-Arnold and Mohamed Salah received confidence boosts by getting on the scoresheet.
Just as importantly, Liverpool looked far more compact and much less vulnerable defensively than in recent weeks.
It wasn't at all bad considering Klopp and his players had just one day on the training ground to work on the new formation.
Alexander-Arnold curled home a beautiful free-kick to set Liverpool on their way early on
Mohamed Salah powered home a penalty to double Liverpool's lead in the second-half
But the big question is whether Liverpool now stick with it or revert to their traditional 4-3-3.
It may only be October but their next three fixtures look absolutely pivotal for the direction of their season.
They travel to the Emirates Stadium to take on Premier League leaders Arsenal on Sunday before hosting Manchester City, currently undefeated and in second, a week later.
In between they head up to Ibrox for the return meeting with Rangers, who could easily be a far tougher proposition on home turf.
So that 4-2-3-1, or whatever it is, will be stress-tested to the limit.
As Klopp enthused about Tuesday night's display afterwards, however, he didn't sound like a manager about to change tack.
'It was a really good defensive performance in a new structure. Offensively, we created an awful lot. I liked it a lot,' he said.
'The way the boys upfront moved together was extremely good for only one session working on it.
'It [the change of formation]