Analysis: Hyundai A-League's great race

A team outside the top two could be crowned Hyundai A-League champions this season, as the competition is in the midst of its most even season since expansion.

Ahead of tonight's final game of Round 22 between Perth Glory and Newcastle Jets, the difference between leaders Adelaide United (39) and sixth-placed Sydney FC (30) is just nine points.

If Glory defeat Newcastle it will reduce to eight, with Perth moving up to sixth on 31.

In the history of the A-League, only one season has seen the top team and the worst-performed side to qualify for the finals separated by fewer than nine points.

That occurred in 2007-08 when there were only eight clubs and the finals included just four - premiers Central Coast Mariners had a three-point advantage over fourth-placed Brisbane Roar.

In the six seasons since the A-League increased beyond eight clubs, the average difference between first and sixth has been 18.33 points.

After Sydney were defeated 3-0 by Melbourne City on Saturday night, Sky Blues coach Graham Arnold was asked if he thinks a team outside the top two can surge to the championship in 2015-16.

"Absolutely. I think that there's nothing between us, Perth Glory and the top team," he said.

"You know, Perth beat Brisbane 6-3, then Brisbane beat the Wanderers [on Friday night]."

In the Hyundai A-League's history, all championship winners have finished in the top two in the regular season, with only two grand finalists having come from outside those positions - Central Coast Mariners (2005-06) and Perth Glory (2011-12), who both finished third on the ladder.

Arnold has effectively given up on the Premiers Plate but remains adamant Sydney could get on a roll in the finals and lift Australia's unique championship trophy.

"The most important thing in Australia is the toilet seat, so we're still chasing top four," he said.

"We knew that the period of the last few months of the league would be heavy because of the Asian Champions League.

Former Mariners boss Graham Arnold with the Hyundai A-League championship trophy.

"That's why I was disappointed with the points we threw away earlier in the season, and as I said before, I would have hoped to be - before the Champions League - four or five points more than what we were and now we have to do it the hard way.

"It's a test of character for anyone."

With finals contenders set to play each other in the final five rounds, it's almost impossible to predict how the table will look when the regular season ends on April 10.

Based on this season's form, however, it appears likely that the difference between first and sixth will be less than 14 points - the lowest margin from first to sixth in the A-League's top six era.

The top two clubs will still have a significant advantage, as they don't have to play in the first week of the finals and then host their semi-finals on the last weekend in April.

But with the likes of Melbourne City - including record-breaking striker Bruno Fornaroli - and reigning champions Melbourne Victory on track to finish outside the top two, those semi-finals will be hard to pick.

Australian football fans should get ready for one of the tightest and most exciting finals series they've seen.