Big games have rarely ended well for Aberdeen in recent times.

Be it cup finals against Celtic, league games against both sides of the Old Firm, or apparently winnable cup ties against the likes of Motherwell and St Johnstone.

However, the Pittodrie side's 2-0 Scottish Cup quarter-final replay win at Ibrox on Tuesday was a third success against Rangers for Derek McInnes' men this season.

They have not managed three wins in a campaign against Rangers since their last title triumph in 1984-85. So what has changed this term?

Breakthrough wins

Winning at Celtic Park on the final day of last season not only secured second place in the Scottish Premiership, but also ended a 10-game losing streak against the champions and heralded a first win of the season against the Old Firm.

Since then, Aberdeen's win ratio against Celtic and Rangers has improved staggeringly from 13% last term to 30% in all competitions since August.

However, those gains have only come against one of those two Glasgow teams. Aberdeen's record in four games against Celtic this campaign is worse than in the same number of games last season, with McInnes' men claiming just one draw after their campaign-defining win last term.

Against Rangers, though, there have unquestionably been huge gains. Last season, Aberdeen lost three of their four meetings; this time, they have won three of six and lost just once.

However, the Ibrox side are currently eight points clear in the Premiership with nine games to play, so a fifth consecutive second-place finish looks unlikely for the Pittodrie men.

Less defensive, but more resolute

Perhaps the most obvious reason for Aberdeen's improved record is that they have been more resolute in these games than before.

Previously, they concentrated on trying to stop the opposition, with McInnes cluttering his XI with defenders. That strategy met with limited success. But this term, Aberdeen have adopted a more attacking approach and that, curiously, has improved their defensive record against the Old Firm.

For example, Brendan Rodgers' Celtic averaged two goals per game against Aberdeen last season. And, even though results have not improved, that figure has dropped to 1.5.

Similarly, Aberdeen conceded an average of two goals every time they faced Rangers last season. This term, its down to just one goal per game. Couple that with their goals scored per game jumping from 0.5 to 1.3 per game, and the reason for the improvement in results becomes clear.

'It's a huge statement' - pundits on Aberdeen's win

Former Rangers striker Steven Thompson on Sportscene

Absolutely deserved winners. Back-to-back clean sheets against the Old Firm teams. For me, their organisation, their desire, their professionalism to carry out their individual roles that Derek McInnes had set them within the team was so impressive. Aberdeen had three Scottish teenagers in their starting line-up. It's sometimes easy to forget that Lewis Ferguson is still 19.

Scotland assistant coach James McFadden on Sportscene

It's a huge statement when you consider that Gary Mackay-Steven, Sam Cosgrove and Shay Logan are missing. Mackay-Steven and Cosgrove have been in excellent form. To bring in three youngsters in their place really sends a massive statement out. Because not only are they in the semi-final but they're also pushing for a second place as well. So psychologically it's a huge blow to Rangers.