Liverpool defender Martin Skrtel believes the understanding between himself and partner Daniel Agger is the secret to the duo's success.
The Reds pairing have become a mainstay at the heart of Kenny Dalglish's side, helping to keep 10 clean sheets this campaign while Liverpool boast the second best defensive record in the Premier League.
The Slovakia international has partnered Agger in the back four on 15 occasions to date with the duo amassing 33 blocks as well as 73 clearances between them.
Skrtel admits he and Agger have a strong off-field relationship while recognising the technical ability of his defensive colleague.
"At the moment it's me and Daniel playing. It's easy to play with him, he's a top quality player and great on the ball," he told the club's official website.
"The understanding between us is working. Away from the pitch he's a nice guy too. We have things in common, such as tattoos and cars. We both have an interest in them and chat about them.
"I don't think it's just with Daniel, I think I have a good understanding with Carragher and Coates too.
"They are all top quality players. It doesn't matter who starts, I think the manager has four good centre-backs to choose from. Any of us can start a game."
The 27-year-old made the switch to Anfield in 2008 from Russian side Zenit St Petersburg but has revealed the return of Dalglish as manager has given him more confidence than ever.
"I played every league game last season," he added. "But, especially during the first half of the season, I didn't feel as comfortable as I do now.
"I think when Kenny and Steve Clarke came in a lot of things changed, not just for me but for everyone.
"I think you can see that on the pitch this season. As a team we have been better, this year I feel more comfortable at the club than ever before.
"I don't think I've deliberately tried to be more aggressive, as long as it's the right level of aggression."
Skrtel has scored twice this season but acknowledges defensive responsibilities must come first while he would be delighted to add more to his account.
"Our first job is defending and not letting the other team score," he said. "If I score it's a bonus. It's more important to protect our goal. With a bit more luck I might get one or two more before the season ends."