The strategic battle between the championship protagonists was already evident in qualifying, where both Mercedes and Ferrari drivers managed to get through Q2 on the ultrasoft tyres: meaning that they will be the only four cars to start the race on this compound in the top 10.

All the drivers used the hypersoft, around 0.8 seconds per lap faster than the ultrasoft, in Q3: which was claimed by Bottas with the fastest-ever lap of Sochi. This was 1.8 seconds faster than last year's pole (set on ultrasoft).

Wear and degradation remained low throughout the hour-long third free practice session this morning, but some graining was noted on the hypersoft due to the cars sliding on the slippery surface.

The shape of the grid was also influenced by grid penalties for a quarter of the field, which will add another strategic variable to tomorrow's race.

Mario Isola: "Strategy was clearly at the forefront of qualifying, so we're going to see an interesting situation tomorrow with the top four cars starting on the ultrasoft tyre, immediately followed by six cars behind them starting on the faster hypersoft. If you add in to this the number of cars starting out of position due to grid penalties, with a completely free choice of tyres, then we could see a big mix of strategies tomorrow. The ultrasoft starters can target a one-stop race, but the situation for those starting on the hypersoft is less clear cut, even though they should be much quicker off the start line."

Check out our Saturday gallery from Sochi, here.