The first Showdown took place on April 20, 1997, where Port Adelaide were victorious. Image: AFL Photos.

WHERE does the Showdown begin?

In 1990, when a new bird - like a cuckoo - takes the nest Port Adelaide had feathered during a tumultuous winter in the belief it was the expanding VFL's preferred choice for a national league licence?

In 1994, when this choice is reaffirmed - and a new set of colours, a new nickname but all the old values of the Port Adelaide Football Club were needed to take to the national stage as the AFL's 16th team (and fifth based outside of the cradle in Victoria)?

In 1997, on a sun-drenched Sunday afternoon on April 20, when Port Adelaide defies the seven-year head start of its neighbourhood rival at Football Park to win the first Showdown?

The Showdown is labelled as a "modern rivalry" for the national game. Yet, the essence of the derby - Port Adelaide against the rest of South Australian football - is as old as organised football in Adelaide.

Remarkably, Port Adelaide is always present at the building of the foundations of a derby in Adelaide's western suburbs - and the Showdown is not, as often said, a "crosstown rivalry" when the competing clubs are separated by just a few kilometres between Alberton and West Lakes.

And when that new bird from 1990 settles in a new nest - taking the old home of the West Torrens Football Club at Thebarton Oval - the Showdown, particularly in AFLW circles, will revive the origins of the second "western derby" established in South Australian football 130 years ago.

In a bizarre way, all three versions of the western derbies in Adelaide have Port Adelaide look across to the opposition bench to see those who once were among their own.

In 1877, the inaugural year of the SANFL (as the South Australian Football Association), it was Port Adelaide versus the short-lived Woodville that was originally the Port Suburban Football Club (that pre-dated Port Adelaide with its foundation in 1868). 

Did the Showdown begin in 1994, when Port Adelaide was awarded an AFL license?

This rivalry - with just one match that played out as a 1-1 draw at Glanville - ended on September 15, 1877 when Woodville failed, for the second consecutive weekend, to garner enough players for its home derby against Port Adelaide at Woodville. Many of Woodville's leading players were at cricket practice at Norwood where they later took their blue jumpers and established a new football club for the 1878 SANFL (SAFA) season on the eastern side of town - and the growing city of Adelaide now did have a true crosstown rivalry to last the ages with Port Adelaide and Norwood.

In 1894, the origins of the second western derby was from a splinter group of junior Port Adelaide players - discontent from being overlooked for regular selection at Alberton - forming the Port Natives Football Club that later became known as simply the "Natives". They were to become based at Hindmarsh (after playing home games at Kensington) and ultimately were badged as West Torrens from 1897.

The first encounter of this western rivalry in SANFL history was on May 18, 1895 at Alberton Oval, in round three of the premiership season, when Port Adelaide won by 44 points (9.7 to 2.5). As the South Australian Register reported on the following Monday: "The match excited a great deal of interest because several of the (blue-and-gold) Natives were at one time playing with the (Port Adelaide) magentas."

Half a century later, the two neighbouring clubs of the west were partners in one premiership and three grand final appearances during World War II. 

One of the greatest - if not the greatest - West Torrens footballers, Bob Hank, always noted he started his legendary league football career in 1944 wearing a black-and-white jumper from the Port Adelaide livery.

Fast forward to 1997 when the western suburbs of Adelaide drew everyone's attention to Football Park where noted Australian artist Pro Hart captured the colour of the first Showdown .... the derby was that big before it had any note written into the record books.

The first Showdown was big and colourful, drawing all attention to Adelaide's western suburbs. Image: AFL Photos.

Showdown I easily could have drawn comparisons to the pioneer derbies of 1877 and 1895 while the opposition benches had key men who once had their hearts at Alberton - club chief executive Bill Sanders, senior coach Malcolm Blight and captain Mark Bickley. As boys they grew up devoted to Port Adelaide; as men they were on the other side of the great divide - just as their predecessors at Woodville in 1877 and Port Natives in 1895 and later as West Torrens.

Sanders and Blight grew up in the Woodville district - before it had league football status from 1964 - making the ritual visits to Alberton Oval to watch Port Adelaide forward Rex Johns torment defenders and delight fans.

"First year at Woodville High," recalls Sanders. "Me, David 'Nipper' Christie - we lived 200 metres apart at Woodville North - would play under-13s for the school on Saturday morning and then be on our bikes to Alberton Oval.

"We would leave our bikes - with quite a few others - at the eastern gate, behind the old scoreboard. And then we would go from end to end of Alberton Oval following Rex Johns or Wally Dittmar.

"I knew all the Port Adelaide player numbers. I can still rattle them off ..."

Bickley grew up in Port Pirie - born and raised in the football-rich Iron Triangle - and defied all the usual allegiances seen around him. He grew up in a North Adelaide SANFL recruiting zone, cheered for Port Adelaide and idolised Russell Ebert as his hero.

He played for the Solomontown Cats at Port Pirie but associated with North Melbourne rather than Geelong in the VFL because "our jumper had the Kangaroo stripes (rather than Cats hoops)."

Sanders' connections with Port Adelaide run very deep - supporter as a kid; work mate as an adult in the banking sector with Port Adelaide stars Ken Tierney, Eric Freeman and Russell Ebert; and a family connection on his maternal side with legendary Port Adelaide administrator Bob McLean.

Many of the key men on the Adelaide bench during the first Showdown were once Port Adelaide supporters. Image: AFL Photos.

"It is quite a strong connection with Port Adelaide until ...," adds Sanders referring to 1959 when the SANFL introduces Woodville and Central District to its seconds and junior competitions in preparation for league admission in 1964.

"And when you are playing colts football against the likes of (later Port Adelaide club president John McBain) that love for Port Adelaide does fall away pretty quickly."

But not respect. Not even when South Australia is clearly divided along the well-worn line of Port Adelaide and the rest for the first Showdown that had a seven-year build up with the events of 1990.

"I always have had respect for what Port Adelaide has achieved on the footy field," says Sanders.

"What happens in 1997 is - with no question - good for footy in this State and the game nationally. The even scoreline on the Showdown ledger tells you how big the rivalry has become.

"I welcomed Port Adelaide's entry to the AFL - and quickly accepted one simple fact. We had to work harder, in all facets of the game on and off the field. This rivalry has brought the best out of both clubs. You might say, when it comes to rivalries this is the one that puts a Bunsen burner up everyone's backside. There is real heat when you have a competitor next door seeking the same prize you are chasing.

"The Showdown spirit goes on all year - not just in a game - as we battle to get a competitive edge on each other within this city and this State. There is no question that this rivalry brings the best out of both teams. 

"On the field, you see that by how often the underdog wins - the game brings the best attitude out of the teams.

"Off the field, the Showdown in great for the town - and for those who win the match and can start the week with a spring in their step."

The Showdown spirit brings the best out of both teams on and off the field. Image: AFL Photos.

Bickley, rejected by North Adelaide premiership coach Michael Nunan who heavily critiqued the country recruit's kicking during the 1988 pre-season at Prospect, went from fearing how the SANFL competition would cope with the advent of an AFL team in South Australia in 1990 to living the one-team theme (and frenzy) for six years.

"Was it really just one team from 1990?" asks Bickley.

"The build-up to the first Showdown does start in 1990 when Port Adelaide does not get the AFL licence and their people are left ... well, let's say 'disappointed' ... The rivalry is building before 1997 while Port Adelaide people are saying had they made it to the AFL they would have the success that we were not having.

"Okay, so now we are both on the AFL agenda in 1997 and we do get to see who can make the most of it. The beauty of the lead-up to the 1997 season is all the attention is on Port Adelaide that summer while we just go about our pre-season with no expectation, even with Malcolm Blight back in coaching.

"That first Showdown in 1997 is bigger than anything we have known. It would have rivalled the build-up to any SANFL grand final and any of those big State-of-Origin games with Victoria we lived in the 1980s.

"This rivalry is like no other in South Australian football, however. We know we had Port Adelaide v Norwood or Sturt or Glenelg ... But where was there a rivalry in South Australian football that made everyone take a side? Where was the rivalry for my South Adelaide that lived up to the Port Adelaide-Norwood moments?

"Now we had - with the Showdown - a rivalry that split the State one way or the other. Port Adelaide or not Port Adelaide?

The first Showdown split the state with all South Australians choosing a side. Image: AFL Photos.

"And there is absolutely no doubt football is better for it. On the field, it has been close; it has had emotions that have spilled outside the game like at the Ramsgate hotel and moments that have united us to remember Phil Walsh (the premiership-winning assistant coach at Port Adelaide in 2004 who died while senior coach of the neighbourhood rival).

"We have had epic matches, some decided by freakish bounces ... (such as the one that came from Angus Monfries' successful shot at goal while Port Adelaide closed the Showdown story at Football Park in 2013 with a 19-16 winning count from the derbies at West Lakes).

"The rivalry also allows each supporter base to look at the local rival - it is the easiest comparison that never ends. And if the rival is doing better than your club, you are asking why can't we do it like them? That always will be there."

The Showdown rivalry began in 1997 or 1990 .... or does South Australian football history say it has been there for more than a century while Port Adelaide stood out as a team and a club like no other?