Daniel Agger and Martin Skrtel, Liverpool's two main central defendersWith fourteen competitive matches having been played this season, it’s startling to see a total of twenty goals in the conceded column. Having built success on such a solid platform under Rafa Benitez, the figures make for even bleaker reading. But why is it that the Reds’ defence and, indeed, Pepe Reina’s gloves have been so porous?

Cast your mind back to the days when Arsenal were known as “boring, boring Arsenal”. Yes, the days of David Seaman, Lee Dixon, Nigel Winterburn, Tony Adams and Martin Keown. It was, and will probably go down in history, as one of the most efficient defenses the top flight has ever seen. Sure, they didn’t exactly set the world on fire at the other end of the pitch, but they were known as boring for one reason: the lack of goals. At either end.

Now you could be forgiven for wondering why the hell we’re rambling on about Arsenal’s best ever defence on a Liverpool website, but there is a point. You see, the thing about that Arsenal team was that the defence was very rarely changed. Ever. They weren’t exactly the type to pick up injuries and, for the most part, when they did they rarely let it bother them enough to take time out of the team.

So, it could be said then that Arsenal’s miserly defence was built on a consistent solid platform.

Fast forward a few years to the Rafa Benitez era when Pepe Reina won three successive Golden Gloves awards for the most clean sheets in the Premier League. He only missed out on a fourth award in five years due to one goal and you may well remember Jamie Carragher and Alvaro Arbeloa almost going at it on the pitch towards the end of the season as the award slipped away from them.

During those few seasons, Liverpool’s defence was, like Arsenal’s of the early nineties, consistent. At the heart of defence, Sami Hyypia and Carra ruled the roost. If they were fit, and they mostly were, nobody else even came close to getting a look in. For the first couple of years, Steve Finnan dominated the right hand side, until age caught up with him and Arbeloa replaced him so impressively. On the opposite side, John Arne Riise, despite his flaws, was rarely challenged for a place. It was a defence that knew itself inside out.

And so, back to the current season. Already, in just fourteen competitive games, twelve defenders have been used in eleven different combinations. Every single game has seen at least one of the four chosen for the previous match changed and in eight games at least three of the four have been changed.

The most utilised back four (Kelly, Johnson, Skrtel and Agger) has been used on three occasions and would, most likely, have been used more if it were not for Martin Kelly’s latest unfortunate injury problems. Only one other combination has played more than one match together – Wisdom, Johnson, Skrtel and Agger.

Consistency, perhaps unsurprisingly, cannot be achieved with inconsistency.

Of course, allowances have to be made for the different competitions and, indeed, varying standards of opposition that Liverpool have faced so far this season. Clearly there are three names that are a shoe-in for the important matches – Glen Johnson, Martin Skrtel and Daniel Agger. The other place, following on from Jose Enrique’s dire run of form, is most definitely up for grabs.

There are options available to Brendan Rodgers, including several products of the academy.

Perhaps the most natural comes in the shape of Jack Robinson. Having made his debut as Liverpool’s then-youngest ever player, Robinson has rarely looked out of place when called upon. Despite his tender years, he shows a maturity in his game that would be expected of one much older. His commitment can never be called into question and, although he doesn’t possess the ability of Glen Johnson for getting forward, he adds good balance to the shape of the team.

It’s clear he needs to be nurtured—nobody wants the kid to end up in the same boat that Emiliano Insua found himself in when Fabio Aurelio missed most of the season through injury and Riise left for Roma—but he definitely has the ability to nail down that spot for many years to come.

Glen Johnson’s versatility, however, offers further options to the new man in charge. Rodgers has not been afraid to deploy the England full back on the left hand side where, arguably, he has played much of his best football. There are many more options on the right hand side too. Martin Kelly has shown all the attributes required to make it, although his long term future probably lies at the heart of the defence. Behind him in the pecking order are Andre Wisdom and Jon Flanagan.

Wisdom has been able to profit from Flanagan’s early season injury problems and has acquitted himself very well on the occasions he has been called upon. He has pace and power and good positional sense. Much like Robinson on the opposite side, he has rarely looked out of his depth and this is encouraging, especially considering that he has been used in the centre of defence up to this point.

Flanagan will be disappointed to have missed his opportunity this season. With Enrique on the way back and Wisdom’s emergence, competition is fierce for the local lad. Fans may remember his last performance in a red shirt – yes, that one against Blackburn.

Up until that point, Flanagan had impressed with his early performances. One wild night led to an extended hiatus from first team duties, although Rodgers has given him words of encouragement and seems to have him in his plans.

As encouraging as the future may be for Liverpool’s back line, nothing can hide the fact that the number of goals being conceded right now is unacceptable. Bizarrely, though, the errors have thus far been attributed to the more experienced members of the squad.

Skrtel has been culpable on several occasions and, disastrously, contributed to the red card Agger received at West Brom on the opening day. Jamie Carragher’s best days are firmly behind him and one has to question the logic of persisting in playing him alongside Sebastian Coates. Surely it would make more sense to play the young Uruguayan alongside one of the defenders he will be playing with in future seasons so he can build partnerships?

Glen Johnson and Steven Gerrard have both been guilty of mistakes leading to goals being conceded too.

It’s clear that the change in style is causing problems at the back. With the full backs being pushed up—in Johnson’s case almost to Dani Alves-like levels—the team becomes vulnerable. It won’t always be this way, but it is right now. As the team becomes more accustomed to the style of play being employed, players will also become more familiar with the pitfalls that can bestow them.

Gerrard must learn the price of his Hollywood passes. In the past, it was these same passes that could open up defences; they still can. But in bygone eras, the full backs were never so far up the pitch and lost possession rarely resulted in overloaded counter attacks.

In the current system, every time Gerrard, or any other player for that matter, gives possession away in this manner, the opposition has the opportunity to exploit the Reds’ defence. On too many occasions this season, these opportunities have resulted in goals being conceded. Of course, the duty is not only on Gerrard to be more careful in possession but on the players around him to understand the system and ensure that these opportunities are kept to a minimum. When the full backs bomb on, somebody needs to drop in between Agger and Skrtel to provide extra strength.

In the past, Lucas Leiva would have done this job and, despite a difficult start to his Anfield career, most would now agree he does it to a very high level. Lucas is another who has been dreadfully unlucky with injuries, picking up another serious injury in the game against Manchester City, just a few weeks after returning to competitive action following a six month lay-off at the turn of the year. Joe Allen has been asked to deputise in Lucas’ absence, but it’s not his forte.

Another aspect of Liverpool’s play that has changed is in the way the players at the heart of the defence utilise the ball. The pass completion rates (91.5% for Skrtel, up from 83.3% last season, and 90.5% for Agger, up from 84.5% last season) show just how much Rodgers encourages them to retain possession. There have been some lapses in concentration that have led to goals (see Skrtel vs Man City), but for the main part this has been a success story.

Another part of their games to have changed, more so in Skrtel’s game than Agger’s, is the regularity with which they look to come out of defence with the ball to make an extra man in midfield and create space for those ahead of them. Agger is as good as anyone in his position at this and did so four times in the first eight minutes against Stoke. It’s a relatively new skill for Skrtel, although he is showing an aptitude already.

The issue with that approach, though, is again with the players around them and how they deal with the change in the shape of the team. If the full backs have pushed up, it then requires two midfield players to drop in to cover, or one of the full backs to make the decision to drop back. When this doesn’t happen, the team is left vulnerable once more to the overloaded counter attacks. It is the simple things like this that are costing Liverpool goals right now, with every chance conceded being a clear-cut one.

Much can be made of individual performances and, indeed, individual errors. It is more important, however, to recognise the flaws in the system and look for ways to address them. Brendan Rodgers is an infinitely capable man and he will be well aware of the problems outlined above.

It will be interesting to see both who he chooses to take the club forward from the back but also how he addresses the issues currently befalling the side.

statistics courtesy of liverpoolfc.com