WHEN ranking the AFL's biggest rivalries, the Western Derby is handicapped by its short history, but there is a case to be made that it is the competition's fiercest match-up bar none.

Colleague Ashley Browne recently ranked the AFL's noted rivalries on Twitter, with Geelong-Hawthorn at No.1, followed by Carlton-Essendon, Carlton-Collingwood and the Showdown in Adelaide.

The Derby came in at No.5. It is a game almost treated as a novelty by some outside WA. 

Sunday's twilight clash, which is clearly the match of the round, presents a chance for the football world to have a good look at what makes the Derby a great rivalry. 

Former Fremantle and Essendon defender Adam McPhee has a broad perspective on such matters, having played in seven Derbies as well as clashes between the Bombers and Carlton (10), Collingwood (13) and Hawthorn (10) in his 223-game career. 

"I would put the Derby up as the equivalent as far as the way the game is played and the intensity and the build-up," he told AFL.com.au.

"You're playing the game on its finest edge and doing everything possible to win. 

"You're basically living on the edge of the rules and testing every barrier that you can.

"There's some genuine dislike for each other between the clubs."

McPhee says there is "probably not a lot of respect" for the Western Derby outside WA because the two clubs are so removed from the Melbourne football hub.

There is also the matter of Patersons Stadium, which has a capacity of 43,500, locking thousands of fans out every time the clubs meet. 

Enhancing the longstanding Collingwood-Carlton rivalry is the supporter aspect, with an average attendance between the clubs of 72,939 over the last 10 years. 

But when the ball is bounced, do those matches in 2013 have the same physical edge that McPhee talks about in Derbies?

For an indication of how big the West Coast-Fremantle rivalry is, consider what a Derby final would be like.

It's something Eagles coach and Derby icon John Worsfold pondered this week.

"It'd be wonderful to be involved in the first final Derby. That's a possibility this year, as it was last year," Worsfold said.

"They're Derbies, they're not a normal [game], playing another team from another state. It's West Coast-Fremantle. It's a wonderful part of footy in this state." 

The balance of this particular rivalry is in an interesting state of flux, with Fremantle enjoying a period of dominance that has seen it win 11 of 15 clashes since 2006, including seven consecutive between 2007 and 2010.

West Coast's most dominant period came in the first four years of the rivalry winning the first nine Derbies.

Those victories helped foster the big brother-little brother relationship that developed between the clubs.

McPhee, however, believes the relationship is changing and says Fremantle is a "sleeping giant" of the competition.

"The Eagles were there first and believed they were a better and more powerful club, but I think that's turning," he said. 

"Fremantle's always been regarded as the second team in the state, but I believe they're now on their way to being respected as a genuine team in the AFL competition that is going to be successful.

"That's the only thing West Coast holds above them, they have the premierships that Fremantle don't."

Nathan Schmook is a reporter for AFL Media. Follow him on Twitter @AFL_Nathan