MONTREAL, Canada -- The decision by Mercedes and Ferrari to qualify on the ultra-soft tyre in Q2, and therefore start on that compound, is a clear indication that they will attempt a one-stop.
Barring Safety Cars or other strategic anomalies, the ultra-soft runners are expected to make a single stop for super-soft tyres around lap 20 to 25. Both of the harder compounds on offer experienced minimal degradation on Friday, while the hyper-soft -- the softest compound in Pirelli's range -- had observed degradation of 0.2s per lap -- a significant amount given that it only offers a 0.5s per lap performance benefit in race pace.
Red Bull, which starts on hyper-softs, will hope to mitigate that degradation in the opening stint, and on Friday appeared to be the only one of the top three teams capable of doing that successfully. That could prove beneficial if they can find clear air after a pit stop on lap 15 as Friday's data suggested the Red Bull had a 0.4s advantage per lap in race trim over Ferrari.
The other ace up Red Bull's sleeve will be at the start when the hyper-soft compound should offer better traction off the line. It's unlikely to be enough to make up a position on its own, but combine it with some aggressive driving through the opening corners and Max Verstappen is in a strong position to attack Valtteri Bottas and Sebastian Vettel further round the opening lap.
In terms of looking after the tyres, drivers starting on the hyper-soft have to be kind to their rears. The hyper-soft compound experienced rear graining on Friday -- the opposite to the front graining drivers suffered in Monaco -- and keeping that under control on a hot, sunny day in Montreal will be tricky. On the plus side, if there is a variation in degradation levels between the two strategies it could provide overtaking opportunities for those who are able to look after their rears and get better traction out of Montreal's slow corners.