It looked like that adage might have been broken this season, with a young, exciting Borussia Dortmund team taking an early lead in the table.
Now though, going into the international break, Bayern are back on top. They’re level on points with their rivals but a string of big wins has boosted their goal difference to +41, seven better than Dortmund’s.
There was a time earlier in the campaign when Bayern manager Niko Kovač, who took the reins in the summer, was under pressure. After four wins in a row to start the league season, they went three without one — a relative calamity for the Bavarians. A month later, the same thing happened.
Since the start of December, however, Bayern have been back at their usual steamrollering best. They've won 13 of their last 14 Bundesliga games, a run that has got them to top spot and has seen wins over Borussia Mönchengladbach, Wolfsburg and Mainz by an aggregate of 17-1.
For Dortmund, it was the 30 days from the start of February that tripped them up. In that time, they drew three, lost one, and picked up a single win against Bayer Leverkusen.
Bayern, who have won the last six Bundesliga titles, once again taking the lead isn’t a surprise, though. Not only do they have the weight of history and bank balance behind them, but Dortmund have been over-shooting their underlying statistics all season.
Both teams are conceding goals at a level that’s in line with expectation, according to Football Whispers’ expected goals model, but that’s not the case in attack.
Bayern are in line with their underlying numbers but BVB have netted 59 open-play goals from shots worth just 44.88 expected goals.
Earlier in the season, these skews were even wider. Going back to before the winter break, Dortmund had been conceding just 0.87 goals for every expected goal of their opponents while for Bayern that rate was 1.17.
This year has brought these rates back into line and that could be key in the title race.
Bayern’s expected goals difference has been ahead of Dortmund’s throughout the season and, in more recent months, it’s rocketed away.
At the end of 2018, Kovač cited a slight change of system as a key factor in the change of form after their difficult October and November.
“We decided we absolutely had to close down the centre,” he explained. “Our opponents usually lie deep and try to play vertically after winning possession.
“Besides, our quick full-backs have been more involved in our play thanks to the change. And the decision to make fewer changes to the starting line-up in the run-up to the winter break was surely another advantage.”
The change certainly worked. You can see in Bayern’s rolling expected goals difference, updated after each match, that their performances level out a bit — no better, no worse than their opponents — for that October and November period. Then they picked up again.
The steeper the line, the better the team has been than their opponents.
Interestingly, no such flatlining appears to correspond with Dortmund’s recent rough patch. Their expected goals have been going at a similar pace for most of the season. The results, then, may just be the rub of the green going against them.
That would be comforting for Lucien Favre's team if they weren't up against Bayern, a team able to move at a more ruthless pace than Dortmund’s underlying statistics have reached this season.
BVB appeared to be firing on all cylinders during the campaign, but it may have been built on good fortune that wouldn’t last.
Their main hope now is that Kovač's side goes through another rough patch. Dortmund’s numbers have been consistently good – after a stuttering start – while Bayern’s have been slightly more boom and bust.
With the Bavarians back in the boom part of this cycle and Dortmund’s sparkle fading, it looks like the Bundesliga will return to being a simple league. One that Bayern always wins.