CELTIC may still trail league leaders Rangers by six points in the Scottish Premiership.
If you know your history Ange Postecoglou does not need to delve too far back into the record books to show that such leads at the summit can easily be wiped out.

If the Australian was looking for any omens as to how his side can wrestle the title from Rangers this season then he only needs to pore over the events of seasons 1997/98 and 2011/12.

Both were pivotal campaigns for Celtic and Rangers.

In the two respective seasons, Celtic lagged behind rivals Rangers in the title race at Christmas.

By the end of the two hard-fought top-flight series, it was Celtic who wore the champion's crown in May.

Yet both seasons are remembered best for two unforgettable moments in Scottish football history.

In 1997/98, Wim Jansen's side shattered Walter Smith's Rangers chances of being the first Scottish club to reach the coveted 10-in-a-row.

READ MORE: Marc Rieper Big Celtic Interview: Shattering the 10, the League Cup win that set it in motion and teammates sick with worry

Then in 2011/12, Neil Lennon's Celtic impressively reeled in Ally McCoist's Rangers who had once held a 15 point advantage over the green and white side of Glasgow in November.

By February 2012, the unthinkable happened.

Rangers went into administration and were hit by a 10 points deduction thus increasing Celtic's lead at the top to 14 points and effectively handing Lennon's men the title.

This year's Scottish Premiership title race is still well and truly on especially with a £40 million bounty awaiting the winners.

There is a wave of new optimism sweeping around Celtic Park as Ange ushered in the New Year with a trio of Japanese signings.

Daizen Maeda, Reo Hetate and Yasuke Ideguchi all put pen to paper as the Aussie finally raided the J-League just as he had predicted and Celtic completed some early January window transfer business.

The Glasgow derby now looms large on February 2nd at Celtic Park.

Just as it was in 1997/98 and 2011/12, this rearranged festive derby fixture could well be crucial to the destination of the Scottish Premiership flag.

Season 1997/98

Dutchman Wim Jansen's arrival from Japan was heralded with howls of derision from certain sections of the media.

Sound familiar?

Celtic got off to an inauspicious start as they lost their first two games of the campaign to Hibs and Dunfermline respectively and were plunged to the bottom of the table.

An eight-game winning run restored confidence levels and by October Celtic were starting to look threatening again at the top end of the table.

At the end-of-the-year, the Scottish Premiership table on December 28 looked like this after every side had played 19 games.

Rangers were top with 42 points while Hearts were in second place on 40 and Celtic had 38. 

Christmas 1997/98 table
1. Rangers P 19 Pts 42
2 Hearts     P 19 Pts 40
3. Celtic     P 19 Pts 38

The New Year derby was vital, if Celtic lost, the Ibrox side would open up a seven-point lead at a crucial juncture in the season,

Goals from Craig Burley and Paul Lambert delivered a win that proved to be the turning point in Celtic's season. 

Celtic Way:
Rangers had 42 points while Celtic and Hearts had 41.

The Hoops carried on unbeaten into early April and on Saturday, April 18, beat Motherwell 4-1 at home after going behind and, 24 hours later, Rangers lost 1-0 to Aberdeen at Pittodrie.

Celtic were three points ahead with three games left.

A week later on April 25, Jansen's men drew 0-0 at home to bottom side Hibernian while Rangers defeated Hearts 3-0 in Edinburgh. Celtic were ahead by one solitary point.

On May 2nd Rangers lost 1-0 at home to Kilmarnock, Celtic could clinch the title with a win at East End Park 24 hours later.

READ MORE: Paul Lambert recalls how Martin O'Neill's Celtic side humbled Ajax in the Champions League qualifiers

Simon Donnelly put Celtic ahead in the 35th minute but with seven minutes left on the clock, a looping header from Craig Faulconbridge fell over the line and the match ended in a 1-1 draw.

Celtic were left two points ahead and only one goal better off heading into the last game of the season against St Johnstone on May 9th. Henrik Larsson subdued some fears by scoring after only two minutes.

One solitary goal from St Johnstone would make Rangers' dreams of 10 a reality again.

But in the 72nd minute, it was ‘Cheerio, 10-in-a-row’ as Harald Brattbakk’s shot found the back of the net to record a famous 2-0 win.

Celtic had won the league by two points thus ensuring a six-point swing since Christmas.

Final Table 1997/98 
1. Celtic P 38 Pts 74
2. Rangers P 38 Pts 72
3. Hearts P 38 Pts 67

Season 2011/12

It was another inauspicious start to the campaign for Neil Lennon's Celtic who by November 5th 2011, were sitting third in the Scottish Premier League behind leaders Rangers, who were 15 points clear of their rivals, as well as Motherwell.

Rangers sat on 38 points while Motherwell were second on 26, with Celtic on 23 in third place.

Incredibly Lennon also threatened to walk away from the job at half-time at Rugby Park as Celtic trailed 3-0 against Kilmarnock in October.

A seven-game winning streak in November and December saw Celtic claw back most of the ground lost on Rangers.

By the time Christmas Eve's round of fixtures came the gap was narrowed to just four points. Celtic’s home game on Christmas Eve finished in a tight 2-1 home win over Kilmarnock but Rangers surprisingly lost 2-1 to St Mirren and the gap at the top was reduced to a solitary point going into the Festive derby fixture.

Christmas Table 2011/12
1 Rangers P20 Pts 48
2 Celtic P20 Pts 47

The Festive derby turned out to be crucial again as Celtic won 1-0 courtesy of a Joe Ledley goal and moved to the top of the table by two points after an incredible 17 point swing had occurred since Guy Fawkes Day.

Between November 6 and March 3, Celtic embarked on a remarkable 17 game-winning run before that was brought to a halt with a 1-1 draw against Aberdeen at Pittodrie.  

In February Rangers went into administration and were deducted 10 points. The gap at the top of the table was increased to 14 points thus virtually handing Celtic the Premiership title they had looked on course to win anyway.

The final winning margin of 20 points was a wonderful achievement for Neil Lennon's men and was all the more remarkable when you consider Lenny had contemplated calling it quits when Celtic trailed 3-0 to Kilmarnock at Rugby Park back in October.  

Allowing for administration Celtic had overseen a points swing of 25 points. 

Celtic Way:

Final Table
1. Celtic P 38 Pts 93
2. Rangers P 38 Pts 73

So there are lessons from the ghosts of seasons past to be learned here for Ange and his Celtic players.

A six points gap differential in the title race may seem like a tall order at this moment in time but it is certainly not insurmountable.

Winning the rearranged Glasgow derby fixture on February 2nd could well be the catalyst for Scottish Premiership title success and the key to unlocking that automatic £40 million Champions League chest.

The Scottish Premiership title race is still very much in the mixing pot.

If any proof of that was needed you need only ask Celtic's class of 1997/98 and 2011/12.