I believe it's much easier to see how much longer Leverkusen can stay at the top and if they really are a team capable of fighting for the title this season, Leverkusen's next games are:

1 - ) Werder Bremen

This is an easy opponent who in the last 5 games has only managed 1 victory, so in this game Leverkusen has a greater chance of winning and would remain at the top, since their biggest opponent, Bayern will be playing against a very weak team that we Last 5 games only had one victory, so the position in the table will not change

2 - ) Dortmund

well, this will be a game that I see as a great test for Leverkusen, Dortmund, despite not having good results in the last few games, is still a strong team that can make Leverkusen lose points, and while Leverkusen plays against Dortmund, Bayern will be playing against Union Berlin which is the worst team this season and Bayern will come out victorious, which means that a defeat or draw for Leverkusen against Dortmund would make Bayern top of the table and never leave until they become champions. Now a victory for Leverkusen against Dortmund would confirm that they are candidates for the title. It's true that after the game against Dortmundo, they will have a difficult game against Stuttgart

This season Bayern has a good squad, and looking at how well they have played, I think that for Leverkusen to have a chance of winning the title, they cannot lose in any game, which is an extremely difficult mission, a single defeat What they have will be a great opportunity for Bayern to stay at the top of the table and it will be difficult for them to leave the top until the last round, because the difference in Bayern's squad in relation to the other teams is very large.