Australia's David Pocock and Michael Hooper, pioneers of the "twin opensides" approach to back-row play, will come face to face with England's copycat version in Saturday's Rugby World Cup quarter-final in the shape of Tom Curry and Sam Underhill.
David Pocock pats Michael Hooper on the head during their Rugby World Cup pool match against Wales Photo: Photosport Ltd 2019
While not unique, it is still uncommon at test level to operate with two specialist sevens and Eddie Jones is a recent convert after being won over by the dynamism of the young English duo he dubbed "The Kamikaze Kids" after pairing them for the first time during the World Cup warm-up games in August.
They are different players, different shapes, different ages and vastly different in experience to the Australian duo, nicknamed "Pooper", but all four will play a key role in trying to dominate the crucial breakdown area on Saturday.
"It's something we're very much looking forward to," Underhill told reporters. "You want to challenge yourself against the best in the world and it's fair to say they're two world class opensides. They're players who Tom and I, when we were growing up and coming through, looked at and inspired to be like, so it's a bit surreal to be coming up against them now."
Hooper, 27, will be winning his 99th cap, while 31-year-old Pocock his 83rd. Curry, 21, has 16 caps, while Underhill, two years older, has 12.
"Technically they are both very good over the ball," Underhill said. "Pocock is probably the best in the world in terms of how strong he is, and his body position. On top of that they have very good timing."
England coach Jones has been hugely impressed with his own dynamic duo and said changes to the way the game is being refereed, encouraging more of a contest at the breakdown, has persuaded him to go down the twinning route.
"I think it's going to be a great contest," he said. "Pocock has probably, over the last 10 years, been the foremost number seven in the world, while Hooper is a massively important player for Australia, but our two young boys are just getting better every game," he said.
"Curry's improved his line-out jumping immensely over the last eight weeks while Underhill's probably the most combative seven I've seen for a long time."
The English pair certainly love the physical side of the game and that battle for every inch of space.
"It's pretty gritty and unglamorous work. You've got to enjoy that and you've got to see how what you're doing contributes to the team," Underhill said.
"When the guys are scoring out wide it's usually because the forwards have done something good in the middle, something that's fairly dull to watch but that creates special moments in the game."
- Reuters