Penrith and Parramatta will reignite one of rugby league's fiercest rivalries in Saturday night's do-or-die semi-final, and only a select few know what it's like to be one both sides of the divide.
There have been 92 players who have lined up for both Western Sydney clubs over the years since Penrith joined the big league in 1967, including four ex-Panthers in the current Parramatta squad – Reagan Campbell-Gillard, Bryce Cartwright, Waqa Blake and Will Smith.
Others include the likes of former international Michael Jennings, 300-gamer Geoff Gerard, premiership winners Paul Dunn and David Liddiard, as well as Andrew Leeds, Matt Adamson, Gary Freeman and Frank Pritchard.
But when you compare it to the number of defections that have taken place in other rivalries between the Roosters and Rabbitohs, Sharks and Dragons or Titans and Broncos, it's still relatively rare for a star in their prime to hit the M4 highway in Sydney's west and switch sides, especially for established stars.
With a 30-minute drive splitting the locations, the fierce rivalry extends from junior rugby league fields to the NRL.
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'It gets drilled into your head'
Eels forward Cartwright has been through the thick of it as a former Panthers player and St Mary's junior.
He was one of the best young prodigies coming through the club's healthy junior system and brought up in a family whose surname is synonymous with Penrith.
"When you're a young footy player from Penrith coming through you're brought up to hate Parramatta, it's just what it is," Cartwright says.
"It's the biggest rivalry for a young western Sydney kid coming through.
"You've got your local club battles but it all falls under the Penrith district. Once you get to represent the Panthers at the next level you know the Eels are your biggest rivals.
"It gets drilled into your head from a young age and it comes out when you're on the field, no matter the level.
"Growing up they always used to be fiery, rough and of high intensity no matter the level.
"When I started playing in the NRL you just knew that they wanted to hit you harder. You felt it a bit more after a game."
Cartwright's time at the Panthers ended in 2018 in a well-publicised exit that left him moving to the Gold Coast.
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The Cartwright surname remains a huge part of the Panthers with the club's major player of the year medal named after his late grandfather, Merv Cartwright.
His father Dave and uncles John, Michael and Cliff all represented the club at some point in their senior careers.
Cousin Jed also snuck in a Penrith debut before shifting to South Sydney.
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But Bryce left the Cartwright family history and connection behind when he made the move to the Titans in 2018.
"I think it's been a bit easier for me to play Penrith this year because I went to another team before I joined Parramatta," he said.
"When I first played against [Penrith] at the Titans I put a lot of thought into it and it felt weird.
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"I think if I went from Penrith to Parramatta there would be a bit more feeling behind it, especially this week.
"But it honestly doesn't feel like my old team anymore, it feels like a long time ago, a different lifetime.
"It took me a little while at the time to detach myself from the club initially but Parra's in my heart now, it's my home."
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Campbell-Gillard feels the same way as Cartwright over his exit from the Panthers two seasons after his close mate departed the club.
As a Panther in 2019 he told NRL.com "as a junior, you come through the system to hate them".
"I also don't like that word but it is. It doesn't matter what form you're in, it's a game you get up for."
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On Wednesday he made it clear he didn't want to leave the NRL's Queensland bubble and return to Sydney on the back of a loss this week.
If his performance against Newcastle last week is anything to go by, Campbell-Gillard isn't going to shy away from coming up against his former teammates.
"I've been here a while now and I call Parramatta home," he quipped.
"I've made it clear we don't want to go home. We'll be doing everything and anything to give ourselves the opportunity for a really good game on Saturday."
Cartwright said he's never seen his Eels teammate in better shape.
"I know Reg [Campbell-Gillard] feels the same way as I do about leaving Penrith and playing for Parramatta," he said.
"I've known him for ages and I haven't seen him in a happier headspace as a person and player.
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"It's just the Parramatta club and the people around it make you feel right at home.
"The rivalry for me has switched now. It's a little strange being on the other side of it but there's no difference when you play Penrith.
"They try and hit you hard, there's a bit more talk and I think this weekend will be no different.
"Both clubs hate each other, it's always been like that and it will never change."
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Cartwright noted he had only played with a handful of the Panthers' current players with Ivan Cleary's side focused on ushering through a next generation of talent in recent years.
It was Cleary who handed the 26-year-old an NRL debut at the Panthers in 2014.
He was one of their best players for the next three seasons before injuries and off-field issues plagued him.
"They're just full of young kids now but very exciting and they play a tough brand of footy under Ivan, Ciro [Cameron Ciraldo] and Wal [Peter Wallace]," Cartwright said.
"They've adjusted really well to the new speed of the game and have become really hard to beat.
"The club has always tried to get to the level they're now at and they've just got a side that plays with a lot more energy consistently than other teams.
"It's hard to contain for 80 minutes and there's so much skill across the park. They're a very hard team to beat."
'They breathe footy out west'
Former premiership-winner Joe Galuvao moved from Auckland to Australia after signing with Penrith in 2001 and despite not growing up in the area he quickly learned of the local rivalry.
Galuvao, who also enjoyed stints at South Sydney and Parramatta before winning a second title with Manly, has remained a Penrith resident throughout his life.
He has dedicated most of his post-playing career in the community, working to deliver welfare, health and education programs for the NRL and now Wests Tigers.
He said the level of interest in the Battle of the West clashes were beyond measure for both communities.
"Those local derbies involve a lot of supporters who are passionate about their clubs, a couple of big supporter bases who want it known they're the best western Sydney club in the league," Galuvao said.
"They've got the biggest junior bases in the game and a lot of them progress through to first grade.
"A lot of those players play against each other from when they're teenagers and that rivalry just follows them up.
"It's big for both communities. I've seen it both firsthand from a community angle and on the field.
"You probably don't realise how much of an impact a game between both these clubs has on a community until you're out of the game and are working within it.
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"When I moved to Penrith it didn't take me long to realise how much they breathe their footy out west.
"As a player who wasn't brought up in the junior system you very quickly buy into that.
"When they're doing good it's amazing the amount of support that is received and it has a flow-on effect in the community and no doubt for both clubs in their brand.
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"It's a shame the game isn't going to be played in Sydney because the community would've really gotten behind the match in a far greater way."
Eels prop Junior Paulo, who came through the club's junior system with Cabramatta, added the match would still be a memorable occasion for those associated with both clubs.
"It would've been nice to be playing it in western Sydney but I think this game is going to be one where we put on a great performance not only for rugby league but for those people back home," Paulo said.
Not all about hate
The word "hatred" gets thrown around when rugby league rivalries are discussed, but Galuvao has a different take.
"I wouldn't personally call it a hatred but definitely a respect there, a healthy respect," he said.
"Both clubs want to be successful and that narrative plays a big part in the mindset of players going into games.
"Ask any player who plays against their former club and there's always that extra grunt in your tackle and fire in your runs.
"In 2009 when I first joined Parramatta it was one I wanted to have a good game in and crack at my former club.
"You're playing against guys who played with, trained with and shared good and tough moments with.
"It's a strange feeling at first but you adjust and I think being on both sides of each club you have a much bigger appreciation for the rivalry."
Fearing the aftermath
While majority of diehard Eels and Panthers supporters will be watching the match under lockdown restrictions in western Sydney on Saturday night, the result in Mackay will sit with both clubs for the entire summer, and possibly longer.
Questions are likely to be asked of the premiership credentials of the losing outfit in one of the biggest battles between the two clubs in history.
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"There's pressure on both for different reasons but I think Penrith a little bit more just with a few guys back and the expectations after losing last week and falling short last year," Galuvao said.
"The expectation on Parra is huge too. They've always been up there recently but haven't been able to take the next step with BA [Brad Arthur].
"I just think Penrith might have too much class. I'm expecting a big game from Jarome Luai. He's been pretty quiet and the way that he plays rubs off on other guys.
"With Dylan Edwards back I also think that will take a bit of pressure off."
For Cartwright, he's just relishing the chance to be back in the finals fold again.
Knocking off his former club would be an added bonus.
Ask any player who plays against their former club and there's always that extra grunt in your tackle and fire in your runs.Joe Galuvao
"This time last year I had no contract, I was back in Sydney watching footy training, now I'm here playing in the second week of the finals and one of the biggest games of my life," Cartwright said.
"It's pretty cool to look back on how hard I've worked this year but I just want to get to that grand final now.
"It's everyone's goal, from November 1 when you start training to now. It should be a fiery game."