If defence wins premierships, the Sydney Roosters face an acid test in their NRL showdown with Penrith on Friday night.

The heavyweight match-up pits the competition’s two best defensive teams against each other and shapes as a gauge of just how far the Roosters have come following a slow start to the year.

Roosters coach Trent Robinson prides his sides on their defence, declaring their reputation is defined by it.

Robinson uses explosive young forward Victor Radley as an example of how defensive aggression is highly regarded at the club.

After 14 rounds, the Roosters (2.3 tries, 15.1 point per game) and Panthers (2.4 tries, 14.6 points) have been the league’s best defensive sides.

Anthony Griffin’s Panthers, led by their well-rounded forward pack, have been staunch in defending their line, conceding the fewest metres in the comp (1243 per game).

On the back of it, they’ve bolted out of the gates with 10 wins from 13 games – an equal club record – that has helped lift them to second on the ladder.

Robinson wants his side to be known for their defence in much the same way.

“Our house is built on that, we’ve been very strong this year,” Robinson said.

“We’ve prepared well, we’re looking forward to that clash.

“And then we’re looking forward to it opening up a bit and showing what we can do with the ball.”

Perhaps 20-year-old rising star Radley is best representative of that mindset.

After just 16 first-grade appearances, the Clovelly Crocodiles junior is already somewhat of a cult figure.

A fortnight ago the Roosters faithful chanted his name as he came off the ground in their win over the Wests Tigers after cutting several opposition players in half with some textbook tackling.

Robinson described Radley as “confident but not cocky” but admitted he requested the coach replay his bone-rattling tackles during team video sessions.

“It’s something that he does but it’s a Roosters style as well,” Robinson said.

“That’s what we do. You can win without the ball.

“It’s not trumpeted in the way that people commentate on our game. People only look at 50 per cent of the game. They’re missing half of it, the other half is the defence.

“You can win without the ball and that’s why those players play in our team.”