Valtteri Bottas admits his past form at the Russian GP offers confidence but doesn't guarantee he'll be competitive again.

The Finn has finished no lower than fourth in every race he has finished in Sochi, even running third before being punted out by Kimi Raikkonen in the only exception in 2015.

In 2017, Bottas took his first Formula 1 win in Russia and last year would have likely won had a Mercedes team order not seen him give up the victory to teammate Lewis Hamilton.

"For sure it gives you confidence to come into a weekend when you know previously it’s been one of the good tracks for you," he said on Thursday. "So that’s obviously a nicer way to start the weekend.

"But always, in every case, you start from zero, every season, every track changes a little bit, every car is always different every year, so setup, everything is different, but for sure, we have a good mindset coming here, knowing that it’s been good in the past."

Asked what his key to success at Sochi, Bottas continued: "I don’t know, just since the first year coming here, I’ve found a good flow on the track and haven’t really had many problematic corners or anything, so I've been on the pace.

"Obviously, there’s always things I can do better this year than last year and that will be the aim."

Success on Sunday was very much be needed if the 30-year-old wants to keep his slim 2019 title hopes alive, however, they weren't helped last weekend in Singapore when another team order meant Bottas had to slow down to remain behind Hamilton again.

“Well, first of all, that was last weekend, I’m not thinking about that any more coming into this weekend,” he said, on if there had been any repercussions.

“I can’t go into details, we always review everything by the finest details with the team. I was in the factory on Tuesday and we had meetings about that and that will keep just for us, whatever we’ve spoken about it.

“We have certain rules both ways, and they are equal. I just need to make sure I won't be in that situation again.”