Wet weather characterised today's action at Istanbul Park, both in free practice and qualifying, causing a 45-minute delay with just over six minutes of Q1 remaining, followed by another red flag three minutes later. A mix of intermediate and full wet tyres were used throughout all three qualifying sessions, with pole set using the intermediate tyre on the final run of Q3.
This made an already slippery track even more challenging, allied to the cool track temperatures of just 12 degrees centigrade.
Red Bull's Max Verstappen went quickest in every session so far this weekend (in both wet and dry conditions) apart from the crucial Q3 session, when Racing Point's Lance Stroll dramatically took pole ahead of him.
As per the rules, the car set-up cannot now be changed even though tomorrow's race conditions could be quite different.
This is one of the hardest races to predict a strategy for, owing to a number of different factors. First and foremost, track conditions. This asphalt is extremely new and slippery, with rapid evolution, but how much grip it will ultimately offer remains unknown. The weather makes those calculations considerably harder, with very cool track temperatures and rain today, while tomorrow's conditions are still uncertain. Finally, there's not much difference between a two-stopper and one-stopper.
On paper, a two-stopper is quicker - but teams always prefer a one-stopper, especially if they can somehow manage to do it on the two softer compounds this weekend. Right now, that seems almost impossible if graining on the soft stays the same as it's been so far, but some teams might still try it. Alternatively, they might still go for a one-stopper using the White hard compound, if they can get it to work. All that obviously depends on what tomorrow's race conditions will look like, so there are plenty of question marks.
In theory, a two-stopper is quickest: with two stints of 16 laps on the Red soft plus a Yellow medium stint of 26 laps (perhaps as the middle stint). Another way of doing it, if there's graining on the soft, is just one 14-lap stint on the red tyre with two 22-lap stints on the medium.
If it's warm enough to switch on the hard compound, the teams could try a one-stopper with 30 laps on medium and 28 laps on hard. Alternatively, 20 laps on soft and 38 laps on hard.
Mario Isola: "The conditions meant that it was hard to draw many conclusions from today, with extremely low levels of grip, cool temperatures, and rain. We only saw the intermediate and full wet tyres used in FP3 and qualifying, with the pole position time set on the Green intermediate as the crossover point was reached during Q3, triggering a tense strategic battle. The marginal conditions and frequent interruptions made driving extremely challenging today, although the characteristics of both the intermediate and Blue full wet meant that there was plenty of opportunity for the drivers to run as many laps as they wanted with the allocation available, as tyre wear in these conditions is very low. As is often the case when it's like this, we have quite a mixed grid for tomorrow, when we expect conditions to be dry. Added to a slippery track and the several options available in terms of strategy - now that all the drivers have a free choice of starting tyres if it's dry - we can look forward to an unpredictable race tomorrow, with several unknown factors to spice up the action. Congratulations to Racing Point for taking the initiative to switch to intermediate tyres first, and then claiming first and third on the grid".
Check out our Saturday gallery from Istanbul, here.