That Amitabh Bachchan leaves his co-stars in awe is well-known but "Teen Patti" director Leena Yadav says the megastar not only spells magic in front of the camera but surprised everyone with his expertise in tennis, violin and piano as well.

"Mr.Bachchan is good in so many things. We were in awe. When we were shooting, we used to play games and we saw how perfect he is in tennis, " Yadav told in an interview.

She said there was a scene in the film where Bachchan's character had to play violin.

"I got an expert to train him and kept telling him that the expert wants to show him how to hold the violin.

But Mr.Bachchan insisted on doing it during the shot. When he came to the floor, the expert was standing to show him but he took the violin, placed it rightly and started playing perfectly. He played the piano also. He surprised us in many ways, " Yadav recalled.

Releasing Friday, "Teen Patti" features Bachchan as a mathematician trying to evolve a thesis on probability by relating it to the Indian card game of 'teen patti'. The film also stars Hollywood legend Ben Kingsley.

Yadav, who co-scripted the movie with Shiv Subramanyam, reveals that the probability theory Bachchan tries to prove is absolutely fictitious, but insists it is applicable to card games to some extent.

"See, probability is a very interesting theory in mathematics. You can even apply it just by logic. It doesn't need an equation there. Also, when a shuffle happens, you can tell what's the probability of the card...

"It can be applied, but obviously a man's mind cannot do it sitting on a table because it involves pages of calculation. So we went through the whole process and then simplified it, " she said.

Yadav said the idea of making a film on the subject was lying dormant in her mind for a long time but the plot developed after she researched on the card scams in the US.

"I always wanted to make a film on the mindset of today's youth where they want to be rich and successful very fast. I read a lot about card scams and did a lot of research on greed and the psychology behind that...Spoke to a lot of my friends.

"All through the process I started finding it more and more interesting. And then when Shiv Subramanyam and I started writing, the characters automatically evolved, " she said.

Before shooting began, Yadav did a reality check on an illegal gambling hideout to know how makeshift casinos function.

"In Mumbai, gambling is illegal. So in different shady places they make temporary set-ups so that they can escape if there is a raid. While shooting I took the creative liberty of shooting it on a set, but before that I visited one functioning 'adda' to have a feel of what exactly happens there. It was quite risky, " she said.

Apart from the two veterans, the film also stars R. Madhavan. And the director is also introducing four new faces - Siddharth Kher, Vaibhav Talwar, Dhruv Ganesh and Shakti Kapoor's daughter Shraddha Kapoor.

Asked why she chose four newcomers, Yadav said: "Mr.Bachchan, Sir Ben Kingsley, Madhavan and the four debutant actors are the primary actors. While choosing these four actors, we were in two minds whether to take established actors or to go with fresh faces.

"Finally, we decided to take these young people because they fit the age they require to play in the film. It took us 8 to 10 months to cast them. We went to different cities for audition and finally chose them."