By his own admission, the 2018 season was the worst of Valtteri Bottas' career. Driving an identical car to the one that secured the drivers' championship and 11 race wins with Lewis Hamilton at the wheel, he failed to score a single victory. But, for next year at least, Mercedes is standing by him.
Bottas' arrival at Mercedes at the start of 2017 came under unusual circumstances. He replaced the outgoing world champion Nico Rosberg, who made a shock decision to retire at the end of 2016, giving the Finn limited time to acclimatise to life at a top-level team. In many ways that took the pressure off Bottas in his first year, allowing him to point to his hasty arrival if results failed to go his way. But in 2018 there was no such excuse and, on paper at least, his performance declined.
In 2017 Bottas finished third in the championship having scored 305 points, three wins and 13 podiums. In 2018 he finished fifth in the championship on 247 points with just eight podiums. He was deprived of near-certain victories in Baku -- due to debris on the track -- and Sochi -- thanks to team orders -- but those footnotes won't be marked in the history books.
To make things worse, Bottas is facing increasing pressure from within the team. Mercedes-backed driver Esteban Ocon is without a drive in 2019 after attempts to manouevre him into seats at Renault and McLaren fell through. As a result, the young and talented Frenchman will spend the year looking over Bottas' shoulder as the team's official reserve driver.
"Yes of course, Esteban is a factor for us in the future," Mercedes boss Toto Wolff told ESPN when asked if Ocon was being considered for a 2020 race drive. "We have options for Esteban for 2020, but of course he might also be an option for Mercedes -- it depends how the season pans out in Mercedes and how Valtteri goes.
"Still, we haven't lost any of our trust in Valtteri. We are 100 percent behind him [Bottas] because there is the trust within our drivers, because if we wouldn't be behind him we might as well make the change now. But we don't.
"We think that he's our man and then obviously Esteban is in the starting blocks because he's keen to drive that car.
It may be sugar-coated, but the warning to Bottas is clear: fail to deliver in 2019 and Ocon will be ready to replace you in 2020.
So what happened to Bottas in 2018? A closer examination of his results shows he dipped in the second half of the year. He rallied in Russia and Japan with two second place finishes, but those were both at circuits where Mercedes had a pace advantage overall. At the final four races he finished fifth each time, unable, it seemed, to extract the same performance from his tyres as teammate Hamilton.
Wolff takes some of the responsibility for Bottas' slump in the second half of the season. With Hamilton facing a title challenge from Ferrari's Sebastian Vettel midway through the year, Bottas was told to play a supporting role until the drivers' championship was won. In Wolff's eyes that excuses Bottas' lack of a victory and the Mercedes boss is convinced his driver will return to the top of his game in 2019.
"I think that for any driver it's very difficult to overcome a situation where you need to back your teammate for a drivers' championship," Wolff said. "I think that is normal when you are taking away the single most important motivation for a racing driver, which is to be able to compete for a world championship. And I think we have seen that effect in Valtteri last year after Spa and this year after Monza. And he knows that.
"I think as long as he's in the hunt for the championship he's going to drive at a very high level -- that is the most important. I don't think it makes a difference whether he wins the races or not, this is because he knows that after the summer he was basically only second in line to win the race. He would have won in Sochi maybe. So on paper he should have had at least two or three wins this season."
But does Mercedes really see Bottas as championship material? On his day he is able to outperform Hamilton, but those days were very much in the minority over the course of the 2018 season.
However, Wolff goes back to Bottas' retirement in Baku, when the Finn retired from the lead of the race with a puncture three laps from the chequered flag. Without that misfortune he would have been leading the championship by a single point from Sebastian Vettel after the first four races, and Wolff believes that could have changed the trajectory of his season.
"If he wouldn't have DNF'd in Baku in the lead, he would've been in the lead of the championship at that point. So things could have taken a very, very different turn at that stage of the season but luck wasn't on his side.
"And I believe truly that it's going to swing towards him at one stage and therefore I'm really looking forward to Valtteri's performance in 2019. And I'd like to hope that Valtteri can add weekend onto weekend at a top level so he becomes a real challenger for the world championship.
"I think he could be in the hunt for the championship [in 2019]. We could come back from the shutdown and have a Valtteri that is very much there driving for his own drivers' championship."