Despite the nominated compounds for Russia being a step harder than last year, the fastest lap times today were actually quicker than their 2018 equivalents, in line with the tendency we have often seen this year.

In addition, there was none of the same graining that was seen on the hypersoft selected one year ago.

Conditions were reasonably cool and overcast for most of the day, with ambient and track temperatures of around 24 and 28 degrees centigrade respectively in the afternoon.

However, the weather forecast is for rain tomorrow, starting tonight. This meant that gathering as much information on all three slick compounds today was particularly crucial, as there may not be the opportunity on Saturday.

Although Sochi has a reputation for being a very smooth track, in reality it's not quite that simple: there's a big difference between the micro and macro roughness. This is one aspect of the track that makes it unique on the calendar.

So far, the performance difference between the medium and the soft is around 0.6 seconds, with a similar gap between the medium and hard.

Mario Isola: "The fact that we've seen quicker lap times than last year despite nominating tyres that are a step harder shows that this was the correct selection for Sochi, in what is very likely to be a one-stop race. Having three different teams in the top three FP2 times, with Ferrari going quickest in the morning and Red Bull fastest in the afternoon, underlines how closely matched the teams are in terms of pace. However, the weekend's action is set to be heavily influenced by the weather, with rain expected tonight that could persist until tomorrow, before a dry race on Sunday. This meant that the teams focussed on collecting as much data as possible today, running all three compounds at length. Each one of them could play an important part in the race, depending on the strategy chosen."

Check out our Friday gallery from Sochi, here.