Lance Stroll said he had no explanation for how quickly his Turkish Grand Prix unraveled, after finishing ninth despite leading the first half of the race.
Stroll, who claimed pole position on Saturday, led away and looked comfortable in the opening stages. That changed after the first stop, when he went from the full wet to intermediate tyre, as he struggled to match the pace of the chasing pack.
Despite objecting to the call, Stroll pitted for a second set of intermediates, surrendering the lead in the process, but continued to drop back through the order. The Canadian was unsure why he had been able to make the best of the tyre.