Mercedes Formula 1 boss Toto Wolff says that his team making fewer mistakes than its rivals was key to it winning its sixth consecutive title double.
Lewis Hamilton sealed the drivers' championship at the United States Grand Prix in what was one of Mercedes' strongest performances since the summer break, as both Ferrari and Red Bull proved sterner opposition.
Mercedes took its titles despite initially appearing to be second-best to Ferrari at the start of the campaign and it faced challenges from Ferrari and Red Bull.
But Ferrari notably made several significant errors that cost it victories in 2019, while Wolff believes Mercedes' lack of mistakes proved crucial.
The crucial title-deciding moments
"Every championship seems like the hardest," said Wolff. "It may be because we are protected by our memory, but certainly this year had its up and downs.
"We came out of the block very strong, didn't have the quickest package on Saturday for a long time, but we able to make the least mistakes on Sunday.
"And that was probably the biggest key to making us win the championship.
"Obviously for me, the highlight is Austin, we came back to old form, winning the title decider with Valtteri, and winning the championship with Lewis with strong pace is for me the highlight of the season."
Asked by Autosport if he enjoyed this year's battle more because of the stronger competition, Wolff said: "We like the fight a lot, and you can see you celebrate the races that are really tough and you are able to win.
"And when we don't qualify on pole but we are able to win the race on Sunday I get 10 times the amount of WhatsApps and SMSs than I get if we're on pole.
"Everybody wants to see a fight out there, and this is what keeps us going.
"So we need these guys strong, competitive, playing with the same rules, and then it's what we love doing."
Wolff also paid tribute to his colleagues and to Niki Lauda, who died in May and had been a non-executive director with the team.
Hamilton had also talked of the impact Lauda's passing had.
Wolff said: "I think the strength of this team is that every single individual, competent playing in his position, contributes to the overall success of the team.
"I don't want to sound like a politician, but it's really the backbone of this team - that we have so many good people.
"Niki had a big part in it, and I'm missing him as a friend, and I'm missing him as a sparring partner, and a travel companion.
"By now he would stand there at the [motorhome] bar and say: 'Lauda is flying, come on, finish the press, we gotta go.'
"And say, 'Well congratulations, what are we doing next year? I think we have not been too competitive in the last few races.'
"And that is missing, that pressure.
"But apart from that what you see on the race track is the tip of the iceberg, lots of performances being made back in the UK.
"It's just overall a really good team effort."
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