New Delhi, Jun 19 (IANS): There was a time when films used to ride on popular screen couples. But not any more! Today filmmakers are not only experimenting with content but are also bringing unusual couples on screen.

From Akshay Kumar-Sonakshi Sinha to Vidya Balan-Farhan Akhtar, filmmakers are trying various permutations and combinations to bring freshness to the silver screen.

According to trade analyst Vinod Mirani, an unusual pairing will definitely become a hit formula but cautions that such experiments need a convincing script.

"An unusual pairing works only when it is needed. When the story demands it, then it looks authentic. Or else one can't just force unusual pairs in a film to make it look different," Mirani told IANS.

So far, one of the most successful unusual pairs has been of Rahul Bose and Mallika Sherawat. They teamed up for "Pyaar Ke Side Effects" and were instant hit at the box office as the people adored their romantic escapades in the rom-com.

When Amitabh Bachchan was paired opposite much younger Tabu and Jiah Khan in "Cheeni Kum" and "Nishabd" respectively, critics were sceptical about viewers' reaction. But much to their surprise, audiences enjoyed watching Big B romancing Tabu and they also appreciated his pairing with Jiah. It was so because it fitted into the scheme of the story.

A typical paring that saw high popularity was when heartthrob Ranbir Kapoor and Konkana Sen Sharma came together in "Wake Up Sid". Not only did audiences enjoy their on-screen chemistry, the film too turned out to be one of the biggest successes of 2009.

Vidya Balan was seen romancing Naseeruddin Shah in "Ishqiya" and later in "The Dirty Picture" and in both the films, they scorched the screen with their passionate romance.

"At times it works at times it doesn't. The story has to be conniving like 'The Dirty Picture' or 'Kahaani', where it should be justified," said Mirani.

The 44-year-old Akshay, who teamed up with 25-year-old Sonakshi Sinha in recent hit "Rowdy Rathore", says age doesn't matter while finalising the cast.

"Age is just a number. Even today I can run better than a person who is half my age. Also, if these young girls look great with us, then what to do?" said Akshay, who will again be seen with Sonakshi in "Joker".

Sonakshi, who started her career with much older Salman Khan in "Dabangg", says chemistry is more important than anything else.

"There is nothing like that, one should not think about it (unusual pairings) so much! After all, the chemistry looks awesome on screen and we saw that in 'Rowdy Rathore', isn't it?" she added.

Upcoming love triangle "I, Me Aur Main" starring John Abraham, Chitrangda Singh and Prachi Desai; "Shaadi Ke Side Effects", for which producer Pritish Nandy has roped in Vidya and Farhan as the lead pair; and Farah Khan-Boman Irani starrer "Shirin Farhad Ki Nikal Padi" are expected to take the trend forward.

"Shaadi Ke Side Effects" is a sequel to "Pyaar Ke Side Effects" and Nandy said that it needed a fresh pair.

"This film demanded fresh faces. We always had Vidya in our mind for 'Shaadi Ke Side Effects'. I believe she really liked the script," he said.

Not only Bollywood, even the southern film industry is trying out the formula and the most recent example is upcoming Tamil period film "Kochadaiyaan", where Deepika Padukone will be seen romancing southern superstar Rajinikanth.