Heading into the winter break, the Bundesliga title race looked wide open. RB Leipzig topped the table with Borussia Monchengladbach in second, two points behind the leaders. Bayern Munich's quest for eight in a row looked to have suffered a major blow as they were five points adrift at the midpoint.
Just three games into the second half of the season and normality has returned. Bayern Munich are top once again and are scoring at will - with 4-0, 5-0 and 3-1 victories since play resumed.
They easily dispatched Hertha Berlin, Schalke and Mainz in those games, but face a much more difficult prospect this weekend as they host second place RB Leipzig. Julian Nagelsmann's side have stuttered since the break, but are the Bundesliga's best hope of denying Bayern Munich yet another league title.
Leipzig are just one point behind Bayern after 20 games, but could see that extended to four points should they lose at the Allianz Arena on Sunday. Borussia Dortmund have also started the second half of the season very well, but remain three points behind the Bavarians after falling to a 4-3 defeat against an unpredictable Bayer Leverkusen and former head coach Peter Bosz on Saturday.
Bayern are also boosted by the potential returns of Lucas Hernandez and Kingsley Coman. The two Frenchmen had missed the start of the Ruckrunde through injury, but are back in the squad this weekend. Wing wizard Serge Gnabry is also in line to start, having proven his fitness over recent weeks.
Hansi Flick has Bayern Munich firing on all cylinders, but almost slipped up in midweek against Hoffenheim in the German Cup, allowing the visitors two late Munas Dabbur goals to see the game end as a nervy 4-3 victory.
"After we went 4-1 against Hoffenheim, we stopped applying pressure and we didn't defend well," Flick admitted.
"We've addressed that in the team. We expect a different performance on Sunday. We showed against Hertha and Schalke that we can focus for 90 minutes"
Over those two games against Hertha and Schalke, Bayern scored nine goals, conceded none and have the potential to record another convincing win on Sunday, even against a team as strong as Leipzig.
The Red Bulls have had their own defensive frailties recently, shipping unneccessary goals to Borussia Monchengladbach and losing twice to Eintracht Frankfurt (2-0 in the league and 3-1 in the cup) in the space of two weeks.
Unlike Bayern talisman Robert Lewandowski, Timo Werner's goals have dried up somewhat since the break, with two goals in the first game back against Union Berlin but none in the three matches since.
Similarly, Nagelsmann's side are the victims of an injury crisis just when it looks as if Bayern's luck is improving. The absences of captain Willi Orban and Ibrahima Konate leave Dayot Upamecano as the only fit centre-back, with Lukas Klostermann forced to play in the middle rather than on the right.
Despite these problems, Leipzig still have an ace up their sleeve - head coach Nagelsmann.
The 32-year-old former German Football Manager of the Year showed his tactical nous in that game against Gladbach, bouncing back from those defensive lapses to secure a 2-2 draw thanks to a major shift in approach after half time.
Two substitutions and a change in tactics saw Tyler Adams move to right-back, while Werner was pushed out wide and Patrik Schick introduced to play through the middle. The switch immediately paid off as Schick found the net within five minutes, before a rocket from Christopher Nkunku salvaged a point.
Leipzig dropped from first place, but the nature of their comeback will give them confidence and hope heading to Munich. Marcel Sabitzer believes that the Red Bulls will have to play to the best of their abilities to come away with anything.
"It's not a nice feeling to lose top spot after two games like these," said Sabitzer after the draw with Gladbach.
"We now need to pull together and get back on track. Going to Munich is never easy. We'll prepare well, in order to get a result there."
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Leipzig's defence could be strengthened by the addition of Angelino, who arrived from Manchester City on loan after Pep Guardiola recommended he work with Nagelsmann.
"Julian Nagelsmann and Pep Guardiola are really similar in how they doing things and in their footballing philosophies. Pep gave me advice about moving to the Bundesliga and said it would do me good," the full-back told RB Leipzig's official website.
Spain international Dani Olmo is another new arrival, having signed on a permanent deal from Dinamo Zagreb last month and was another key player against Gladbach, coming off the bench during the second half. He netted his first goal for the club in the cup on Tuesday and could be in line to start this weekend if Leipzig want to spring some surprises.
Flick's Bayern XI will be predictable on Sunday, with the biggest question mark coming over if Hernandez will be fit enough to start at centre-back. Leipzig's XI, on the other hand, is less easy for pundits to predict.
Former Hoffenheim boss Nagelsmann will have been planning for this game since the winter break. It is the biggest game of their season and probably the biggest game in the entire Bundesliga season.
On current form, Bayern Munich look unstoppable at the moment. But if anyone can stop them winning on Sunday and winning the title, it's Nagelsmann's RB Leipzig.