Once described as a "first-lap nutcase", Romain Grosjean says he has now learned to control his aggression and use it to his advantage.

Grosjean got his first full season in Formula One off to a bad start with a series of early-race incidents, including a four-car pile-up at the first corner of the 2012 Belgian Grand Prix. He was banned from taking part in the following race in Italy but just three races later hit Mark Webber at Turn 2 in Japan, leading to the unfortunate "first-lap nutcase" nickname.

Two seasons later and Grosjean has a very different reputation, built on a series of good performances in 2013 and a year without any major incidents in 2014. Speaking about his early career, Grosjean said he managed to pinpoint where he was going wrong and now uses his aggression to get the most out of his car.

"I've been learning a lot and if we take 2012 it was always in the same place, it was always at the start and it was a mistake from taking the wrong objective as the start was going on," he said. "When you learn that and you understand what you're doing wrong then you can change.

"I think then the aggressivity I can have driving in qualifying is my strength as well. You can do a good lap and then in the race at some key moments it's important to have it. Of course you need to control it and you need to know that there is 500 people working hard for you to build a car and they don't want you to crash."

Grosjean still has a reputation for taking on brave overtaking manoeuvres, including a remarkable move around the outside of Felipe Massa at Turn 4 in Hungary two years ago for which he was later penalised for having all four wheels off track.

"You don't want to do something crazy and take stupid risks. There is a lot in a very short amount of time when you decide to go for the overtaking manoeuvre there's a lot going on so you have to think 'Is that a good place? How is it going?' And you don't want to crash. It's intense inside the car, there's a lot to think about and that's why taking the right or wrong decision is not being stupid or too brave it's just that sometimes you can point to little things to getting it right or wrong."

This year Grosjean attempted a bold move around the outside of Sergio Perez in Malaysia only for the Force India to make contact with the rear of his car and pitch him into a spin.

"You do calculate the risk. Like Malaysia on the outside of Turn 12 that was a bit of a risky one. I assumed Perez would give me room, which basically didn't happen.

"I think it's good for the show, I've always been an aggressive driver, sometimes too much but I think that overtaking manoeuvre was working and then I would have had the DRS to get [Nico] Hulkenberg which would have been two places straightforward. So I like it."