Cologne - It does not take a mathematician to work out that four cannot go into two, but that is the equation FC Bayern München's defenders have had to get their head around for much of the season.

After it seemed like Pep Guardiola was going to play with three central defenders this term, the Catalan coach has instead opted to start with a straight back four in the majority of Bayern's matches. The return of Holger Badstuber from injury and the summer signing of Medhi Benatia has therefore left him with something of a dilemma, albeit a positive one: which central defensive partnership works best for Bayern?

To help him solve that conundrum, has run the rule over the four candidates at the 44-year-old's disposal...

is arguably in the prime of his career, not least since inspiring Germany to World Cup glory last summer. Previously used as a full-back both at former club Manchester City FC and at Bayern, he has made the central defensive position his own while holding on to the skills he learnt in a wider position: strong in the tackle, both on the ground and in the air, he has everything a modern defender needs with assuredness on the ball and, when required, an eye for goal. Boateng's versatility means he offers advantages in a back four or a back three, but his disciplinary record of five red cards is a slight cause for concern.

Like Dante following his arrival from Borussia Mönchengladbach in 2012, it was suggested would need time to settle in at Bayern and that he would have to wait patiently for his chance, but the 27-year-old wasted little time in proving his doubters wrong. The Moroccan stopper arrived at the Allianz Arena toughened up after four years in Italy's Serie A, where defending is regarded more as an art form. Medhi is a maestro in this department, more comfortable than many midfielders on the ball having completed over 90 per cent of his passes since his arrival from the Italian capital. He can be a little overzealous in the tackle, though, which earns him a fair share of yellow cards.

The aerial battle is where Brazil international excels. The former Gladbach man's overall presence on the field gives him an advantage over opposition attackers before they even have the ball, and when they do, bearing down on them with his burly appearance is often enough to frighten them off. He is not afraid of holding a high defensive line and with an average of over 100 touches per game, the 31-year-old is more than comfortable in possession of the ball. Dante also has the pace to chase back when required, but he lacks the same versatility as Boateng.

With labelling "one of the best defenders in the world," we will leave it to Guardiola to explain exactly why the Memmingen native is held in such high regard in Munich. "He has many great qualities. He's good in the air and quick, but he has truly outstanding quality in the build-up," said the Catalan. The Germany international's injury history must be the only real concern, with the 25-year-old spending the majority of the last two years on the treatment table. When he is fit, though, Badstuber certainly makes his presence felt with a whopping 83.1 per cent of his attempted tackles ending in his favour.

Each of Guardiola's choices brings something to the table, but that does not necessarily answer the question as to which two centre-backs produce the goods together. Boateng and Dante have been Guardiola's first-choice on eight occasions, earning 19 points, while Bayern have won all three games in which Benatia has partnered the Brazilian. Boateng and Benatia have won 13 points from their five games in the heart of Bayern's defence, and Badstuber has also yet to lose in a two-man central pairing.

Boateng was partnered by David Alaba and Juan Bernat in a three-man back line in Bayern's 2-0 win over 1. FC Köln on Matchday 6, while Guardiola also opted for a defensive trio for the Matchday 2 draw with Schalke. Since then, four at the back has been his staple, and it was that system which brought success against Hannover on Matchday 25 after his initial choice of three defenders was abandoned half an hour in. Two in the middle therefore seems to work best, but deciding which two centre-backs work best together is an unenviable task indeed.