Nico Rosberg targets Lewis Hamilton's F1 start weakness

Rosberg's F1 championship lead shrunk to nine points after Montreal, where he fell to ninth in a Turn 1 brush with eventual winner Hamilton and could only recover to fifth.

Hamilton has lost ground at the start in several races this year, and Rosberg is determined to keep exploiting that even though he came off second-best last weekend.

"Lewis had a disastrous start, I had a mediocre one, what do I do?" he said of the Montreal situation.

"I'm on the outside, but if I accept to just let him go through then I know I'm behind him and that's it - I'm stuck behind him for the race.

"I know it's going to be risky on the outside because there have been occasions where in the past he knows how to make it difficult, and fair play.

"In Barcelona it worked out really, really well - I tried exactly that thing and it worked out awesomely so that was in the back of my mind.

"He's been having difficulties in starts and first corners lately, it's not been his strength at the moment so [in Canada] I said 'give it a go, go for it, give it a shot' and it didn't work out.

"Of course I can't calculate that I'm going to drop all the way down to ninth.

"I didn't know that, I gave it a go and that's it."

Asked by Autosport what he would do in the next similar situation, Rosberg replied: "The same thing.

"You can't compare one situation to the next, it's one more learning experience for me in the battle with him.

"I just have to see how it goes, and decide in the moment what approach to take.

"At Barcelona that move would have won me the race, in Montreal it went the other way.

"On the next battle I need to make sure I'm on the inside and that's it: I'll be in a stronger position."

He added that he had not been thinking too much about his championship lead when it was a comfortable 43 points two races ago and would maintain that stance now it had dwindled.

"I've been saying I haven't been counting points - I haven't been before, I haven't been now," Rosberg said.

"I've wanted to win the races. The last couple of races, it didn't work.

"Now I'm here and I want to win this race because that is the best approach for me to have: to get the best out of my race weekends."