Indeed, Leverkusen way of playing is really impressive. But on matchday 13 Leverkusen was hold to a draw by the Dortmund team, although in that match Leverkusen performance really impressive, but Dortmund was also not bad.
Right now, I'm really worried to Leverkusen. Because now the difference points between Leverkusen with Bayern Munich is three points, but Bayern Munich has the advantage because they have a postponed match. Also, if Bayern Munich can win in the postponed match, then they will also have advantage because their goal difference is more than Leverkusen.
I am quite sure that Bayern Munich will win their postponed match against Union Berlin so that they will take over the position of leader of the standings, but the postponed match has not been rescheduled when it will be held, so Bayer Leverkusen will still be in first position, but there is a second opportunity for Bayern Munich to shift Bayer's position because their competitors will again face a quite difficult match next week against Stuttgart.
Bayer Leverkusen in the match against Stuttgart may not yet experience defeat but if the result is a draw it will again give an advantage to Bayern Munich, so Xabi Alonso has to be aware of this and sometimes it is a sign of decline because his team cannot recover quickly to widen their point lead again with Bayern Munich.