Toto Wolff says Lewis Hamilton hasn't shown any weakness in 2017

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Toto Wolff says Lewis Hamilton hasn't shown "a moment" of weakness throughout 2017, something he believes is due to how the Englishman reacted to losing last year's championship to Nico Rosberg.

Hamilton stands on the cusp of a fourth world championship after scoring four wins in the five races since the end of the summer break. His lead -- which stands at 59 points -- has been bolstered by misfortune for Sebastian Vettel at the last three races and is large enough that he could wrap up the championship at the U.S. Grand Prix on October 22.

Mercedes boss Wolff is impressed with how Hamilton has approached this campaign, which has seen Mercedes' dominance challenged by a resurgent Ferrari.

"My experience of sportsmen, and the same applies to Nico, is it's almost inspiring the way we developed and looked at the weaknesses and improved the car and out of car," Wolff said. "Lewis, over the winter, has analysed what went wrong and since then we haven't seen a moment of weakness."

Though many seem to have already crowned Hamilton the 2017 champion, Wolff thinks Ferrari's recent run highlights how quickly things can turn around.

"If four races ago I was going to tell you that Sebastian was going to DNF two times and not score well one time then you would have said it was almost impossible. This is motor racing, a DNF or two and suddenly the whole thing swings around.

"We had this situation internally in the team and you can say that it's easier to manage because the team knew it was going to win but you've got to remember when Nico broke down in Singapore [in 2014] that meant the end of the championship or was a big blow to his chances in so far that we can relate to it.

"The Ferrari guys will certainly be feeling awful. I get on very well with them and with Maurizio and its not a situation you want to be in."