Goal breakdown: Arturo Vidal highlights mistakes during Mainz's game winning goal

Bayern Munich's defense has been the topic of entirely too much conversation lately. From the complete absence of centerbacks to their lack of aerial ability to their ability to contain a counterattack, the last six weeks of Bayern Munich have been all about defense, defense, and more (not playing) defense. While it hadn't truly cost them up through Tuesday, it cost them on Wednesday as a series of poor mistakes from the Bayern defense opened the door for Jhon Cordoba to grab a later winner for Mainz 05.

The sequence starts with Arturo Vidal giving the ball away in very uncharacteristic fashion. From this advanced position, Mainz are already in a good position to launch an attack but with four Bayern defenders behind the ball it's not their standard do-or-die counterattack defense. Cordoba gets the attack started picking up the loose ball following Vidal's atrocious header and moving the Mainz attack into midfield. To his credit, Vidal has tracked back covering the run of Christian Clemens while Bernat and Costa move to double team Daniel Brosinki on the wing.

As play continues and Brosinki receives the ball, Julian Baumgartliner swaps with Christian Clemens -- moving to occupy between the Bayern lines -- while Vidal has stopped tracking his run as play has moved wide. While Clemens stays centrally, both David Alaba and Medhi Benatia move to double team the striker should he receive the ball. With both centerbacks moving to occupy Clemens near-post run, Baumgartliner makes a run to support Brosinski by overloading the right side of the field. Really this developing situation is all on Vidal as he should have been tracking Clemens run as he's the lone defensive midfielder on the pitch at this point and this is coming from his area.

Flash forward a run down most of the Bayern half and Bernat and Costa's inability to stop Brosinsk. Baumgartliner has arrived to support Brosinki trailing Arturo Vidal who's rushing to catch up with the play. With David Alaba occupied in single cover (which seems more and more necessary given that Bernat doens't seem to be able to stop a fly during this play), Benatia has moved high to prevent Christian Clemens from turning on goal. With Rafinha occupied on the far post with Samperio, there is a massive hole at the top of the box.

With Baumgartliner, there are two good options for Vidal: (a) either continue with Baumgartliner and force the double team with Alaba or (b) drop off and move centrally to occupy Clemens while Benatia moves to play single cover as Alaba moves up to deal with the run. Both options leave Bayern Munich exposed in some area but Vidal chooses (c) in that he challenges Baumgartliner directly as he receives the pass, going with the all-or-nothing option.

A quick two-pass sequence, one executed turn, three points for Mainz, and suddenly Borussia Dortmund are a six-pointer win on Saturday from making this the tightest Bundesliga title race in the last five years.