The fortunes of Cardiff City and Swansea City could barely have been more contrasting this year.

Albeit in a lower division, the Bluebirds have been vastly out-performing their South Wales neighbours virtually all season since August, much to the irritation of everyone in SA1.

And while the impact of Carlos Carvalhal has given the the Swans a good chance of clinching of Premier League survival, the story of the campaign will be one in which Cardiff have thrived and Swansea have struggled — whatever the outcome for both sides in their respective battles.

It may mean, however, that we see a South Wales derby next season for the first time in more than four years.

So what does the 2018/19 campaign hold for Cardiff and Swansea? These are the four possible scenarios and how likely the bookies think they are, with a derby — in either division — a distinct possibility...

1. Both teams are playing in the Premier League

It has only happened for a single season, but providing Carvalhal can keep the Swans above Southampton and Stoke and Neil Warnock can secure a win in Cardiff's season finale against Reading, it will happen again.

It was one win apiece in South Wales derbies in 2013/14 with Swansea winning 3-0 in Garry Monk's first game in charge after a Steven Caulker header had given the Bluebirds a 1-0 triumph earlier in the campaign.

With Cardiff coming away with a huge win from Hull on Saturday to stay in second place, this scenario needs Warnock's men to match or better Fulham's result on the final day of the Championship season and ensure automatic promotion.

It also needs the Swans — only a single point above the Premier League — to earn positive results against Bournemouth, Stoke and Southampton in their three remaining fixtures.

A Premier League derby between the rivals would be a dream scenario. It would be a potentially enormous occasion for Welsh football, which is still riding the crest of the Euro 2016 wave and has Manchester United icon Ryan Giggs as its new figurehead.

2. Cardiff in the Premier League, Swansea in the Championship

As unpalatable as this seems for Swansea fans, it's still a distinct possibililty.

With Cardiff odds-on to get over the promotion line, only a slump from the Swans at the season's end will see this one happen.

You would still back Carvalhal's men to put their recent bad patch behind them and get the necessary points to survive. They have a much easier run-in than relegation rivals Huddersfield, even if the Terriers have a two-point advantage as things stand.

Yet if this one plays out, it would represent a seismic shift in Welsh football; potentially the first campaign Cardiff have been in the Premier League without being joined by Swansea.

(Image: PA)

3. The status quo remains: Swansea in the Premier League, Cardiff in the Championship

Still a possibility if Cardiff conspire to lose or draw against Reading next week and Fulham beat Birmingham, providing of course Swansea can get themselves clear of trouble.

That would mean the Bluebirds drop into the play-offs, which would seem disappointing given what has happened this season.

With the likes of Aston Villa, Middlesbrough and Derby likely to be there, it would be a daunting prospect for Warnock's troops and they may not get the job done.

Fear not, Swans fans, the status quo may yet be maintained.

4. Both clubs in the Championship

This scenario gives Welsh fans the South Wales derby they've been craving for four seasons, but it would come without some of the glamour of a Premier League rivalry. That's a serious caveat.

With both clubs having spent a long time in English football's second tier, maybe this outcome would feel less a symbol of their decline and more a sign that things have reverted to the norm.

(Image: Huw Evans Picture Agency)

Don't tell Warnock that though, he's desperate to earn a record eighth promotion with the Bluebirds.

Should the worst occur, however, and Cardiff and Swansea both end up in the Championship, both would surely be targeting promotion and any derby game would be hotly contested.

This one seems unlikely as both teams are in decent shape to claim a place in the 2018/19 Premier League.

The odds

Cardiff to be promoted: 1/6

Cardiff to miss out: Evens

Swansea to be relegated: 11/5

Swansea to stay up: 2/7