The concept of left and right central defenders, and so on

Owing to the injury sustained on Saturday by Steven Taylor, which is set to prevent his acting on the playing field for the rest of the season; to a niggling injury which is going to rule Coloccini out for the next couple of weeks; and to Mike Williamson's ongoing injury problems, Newcastle are currently without a recognised centre-back. We may give Tamas Kadar a squad number and he may feature at some point over the next few weeks, but it seems likely that we will go into the next game with Danny Simpson and James Perch as our centre-back pair.

In short, we could have done with a centre-back in the summer, but we didn't sign one, and given Taylor's injury we are in desperate need of one come January. Mike Williamson did a good job for us in the Championship and for a time in the Premier League last season, and in theory, whilst he's missed all of this season so far, he shouldn't be out for too much longer; yet I've always considered Taylor the more capable player and I would ideally like us to sign somebody who could go straight into the first team, to play alongside Coloccini.

For the last three seasons, Coloccini has played for us as the left-sided centre-back, with Williamson or Taylor playing to the right of him, and with Coloccini over that period establishing a good relationship with Jose Enrique and Jonas Gutierrez on our left flank. In the short term, player for player I prefer Kadar to Simpson or Perch; in the longer term, an early player being linked to us for January is Sebastian Bassong; and both of these players are left footed. Though I like both, my inclination is that this makes them far from ideal partners for Coloccini, who I wouldn't happily move the few metres across the pitch.

I was wondering what we think about the concept of left and right central defenders (and the discussion can be extended to central midfielders, and in a more limited or perhaps more complex way forwards): do we accept unanimously that central defenders have a side; how easy is it for them, what decline in performance should be expected, if they are asked to change sides; are there types of player who should prove more comfortable with or alternatively more susceptible to a change; what are some specific examples? In a sort of standard four-man defence, is it even the case that a left-sided centre-back should generally fulfill a certain role, with a right-sided centre-back being a different animal altogether; or does it only matter that the two centre-backs complement each other and together have a range of qualities?

Nice one Bash. It is an interesting question. I'm not sure that the left CB has to be the cultured ball player defender whilst the right CB has to be the thug. I think it is like you say, they just really need to compliment each other. Now I have heard people say that it is important to have a left footed CB and a right footed CB. I've even heard that the right footed player should play as left CB and vice versa so that the players are going on to their strong foot as they play towards the middle (the more dangerous area of the pitch).

For Real Madrid Pepe seems to be able to switch from left to right CB. When he plays with Carvalho he usually plays more on the right but when he plays with Sergio Ramos he usually moves to the left. Ramos too seems to be able to play both sides as when Ramos is paired with Albiol he plays on the left. But both Pepe and Ramos are pretty good with the ball. So perhaps that is the key, if one of the defenders is not so adept with the ball at his feet, he should be made to play on the side (whichever that happens to be) he is more comfortable and then the more 'footballing' CB can change to whichever the other side might be.

I think Germany vs. England at WC 2010 showed how important it can be - John Terry has been used to playing LCB for club and country, and with King (can play both sides) and Ferdinand (predominantly an RCB) both out and Carragher not impressing, Upson was played at LCB with Terry moving to the right. As we all saw, it was a disaster.

Also Fergie had made a recent change (from the Guardian):

Centre-right coalition

Sir Alex Ferguson hasn't given a specific reason why Nemanja Vidic and Rio Ferdinand have swapped sides in the last month. Vidic used to be the left-sided centre-back, Ferdinand played to his right – but since the home win against Sunderland last month, they have been the other way around.

Theories abound, but Vidic seems to want to keep the true reason a secret. "Sometimes the manager wants to try new things or make a tactical change, as he did against Sunderland," Vidic told United Review. "It's no problem for me to play on the right or for Rio to play on the left. We can cope either way. The boss had a reason why he wanted Rio and I to swap against Sunderland and it worked well."

United's right-back – whether it be Chris Smalling, Jonny Evans, Rafael or Fábio da Silva – is always inexperienced, and perhaps Ferguson wants Vidic's experience on that side, with Ferdinand frequently out injured. Or perhaps he wants Ferdinand to be sweeping up behind Patrice Evra, who has often been caught out of possession this season.

Jaime wrote:Nice one Bash. It is an interesting question. I'm not sure that the left CB has to be the cultured ball player defender whilst the right CB has to be the thug. I think it is like you say, they just really need to compliment each other. Now I have heard people say that it is important to have a left footed CB and a right footed CB. I've even heard that the right footed player should play as left CB and vice versa so that the players are going on to their strong foot as they play towards the middle (the more dangerous area of the pitch).

For Real Madrid Pepe seems to be able to switch from left to right CB. When he plays with Carvalho he usually plays more on the right but when he plays with Sergio Ramos he usually moves to the left. Ramos too seems to be able to play both sides as when Ramos is paired with Albiol he plays on the left. But both Pepe and Ramos are pretty good with the ball. So perhaps that is the key, if one of the defenders is not so adept with the ball at his feet, he should be made to play on the side (whichever that happens to be) he is more comfortable and then the more 'footballing' CB can change to whichever the other side might be.

If the CB plays with the stronger foot towards the centre of the pitch, when they cover for the fullback on the same side then they are covering with their weaker foot. However I do think they have a greater choice of passing open to them, instead of just passing to the fullback or hitting it high to a target man.

Overall though I think players get used to playing on one side, and although they can switch (and often do during a game) they not completely comfortable with it and may be more likely to make mistakes.