Arsenal legend Martin Keown believes that the current centre-back pairing of Per Mertesacker and Laurent Koscielny is among the greatest in the club's history.
The Gunners haven't lost a match for almost two years in which the duo have completed 90 minutes together, and have become the key part of a solid defence that has guided Arsenal to the top of the Premier League and progress in the FA Cup and Champions League.
"Arsenal have had some excellent defensive partnerships over the years but there's no doubt that Laurent Koscielny and Per Mertesacker are now right up there with the best of them," Keown told the Daily Mail. "The great thing about the pair is how well they complement each other.
"They are quite different players but they cover each other well and between them have all the attributes you need to defend against anybody. Mertesacker is strong and excellent in the air. He is so tall that sometimes he doesn't even need to get off the ground to win the ball. Then you have the agility and anticipation of Koscielny. He loves defending and it's almost like he has ABS brakes the way he can turn and move.
"Mertesacker seems to be a natural leader. He's the one dictating where the line is and how deep they drop. When he first arrived he looked laboured and his decision-making was not great. Now he makes the right calls and is the sharpest I've seen him, while Koscielny is learning from his experience."
"Against Everton, Romelu Lukaku looked like he might cause damage with his pace but Koscielny policed him, then Mertesacker dealt with Christian Benteke's aerial threat on Monday night. It's that balance and solidity that makes them the best centre-back partnership in the league."
Keown played alongside Tony Adams and Steve Bould in arguably Arsenal's best partnership of all time.