The race where the pre-race model was wrong about everything except the number of stops
Pirelli said medium to hard, one stop, laps 21–27. The winner ran soft to medium, stopped on lap 31 – and would have lost 37 seconds and two places by following the model. Montreal was cold, freshly rained on and rubbering in faster than the tyres wore: all three compounds had zero degradation, the hard was the slowest tyre, and what decided the race was a Mercedes stopping on the track. Russell was leading when the car died. His retirement gave the field its free stop and Antonelli the win.
After four races the teams had a message they could trust: the 2026 tyres often lasted far longer than expected. Montreal asked a different question. Pirelli brought, as in Miami, the three softest compounds – C3 as hard, C4 as medium, C5 as soft. The 2024 surface was still smooth and low-abrasion, and the track evolves quickly because it is hardly used the rest of the year. Graining had been a problem in 2025, but Pirelli expected the 2026 construction to ease it, according to F1.com.
The big question mark was temperature. The race had moved in the calendar and was expected to be colder than usual, and on a stop-and-go circuit with low lateral loads getting heat into the tyres is already hard. That made the C3 hard problematic – and gave the C5 soft a property almost as important as its speed: it was the quickest to warm up, according to F1.com.
The sprint weekend gave only 2 hards, 4 mediums and 6 softs per driver, but the sprint provided a data point: the soft worked considerably better over distance than expected, with linear and limited degradation. The C5 was not just a qualifying tyre, according to F1.com.
Even so, Pirelli's fastest strategy was traditional: medium to hard, stopping on laps 21–27. Soft to hard stopping on 17–23 was the alternative, and hard to medium with a late stop around laps 38–44 gave drivers further back a chance to wait for a Safety Car or VSC, according to F1.com. One stop, then. What Pirelli could not forecast was the weather.
It had rained. The track was damp, more rain threatened, and there were two extra formation laps. The field split. McLaren put both Piastri and Norris on intermediates; so did Audi, Cadillac and Sainz, according to press.pirelli.com. The reasoning is easy to follow: a small loss if it dries, a big gain if the rain comes. Piastri said afterwards that the track had got quite wet between the anthem and the start, according to F1.com.
The problem was that the small loss was not small. Norris actually led the first lap – on intermediates. Then Piastri stopped on lap 1 and Norris on lap 2, and after the out-lap Norris was 20 seconds behind the leader, Piastri 24. Pirelli's Dario Marrafuschi called it what it was: a gamble that did not pay off, according to press.pirelli.com. Cadillac's Allan McNish pointed to what made the decision questionable even as it was taken: the delayed start and the extra formation laps gave the track time to dry, according to F1.com. A tyre choice can be rational ten minutes before the start and wrong when the lights go out.
Those who chose slicks had one more decision. Gasly, Colapinto and Lawson took the medium; almost everyone else the soft, according to press.pirelli.com. That sounds like the opposite of conservative, but in Montreal the logic was inverted: on a cold, slippery track the soft gave better warm-up, better grip immediately and less risk of lock-ups. Pirelli noted afterwards that the cold pushed the teams to the softest compound simply to reach the working window.
The data says it cost nothing. Field base pace on the soft was 76.88, on the medium 77.01 – 0.13 seconds – and on the hard 77.81. And degradation was negative on all three: the cars got faster as the tyres aged, because the track rubbered in faster than the rubber wore. The model clips α to zero. Gasly on the medium gained 0.14 seconds per lap with every lap.
Russell had pole but started badly: P3 after the first lap, P2 when Norris stopped. Antonelli led. On lap 10 Russell took the lead back, and Antonelli then sat 0.3–0.6 seconds behind for twenty laps without getting past. Montreal has the lowest overtaking threshold in our calendar, 0.65 seconds, and still it was not enough. Mercedes said afterwards they had had no idea how the tyres would behave in the cold, according to F1.com. They learned as they went – and the lesson was that the soft was not wearing at all. "When must we leave the soft?" became "why should we stop at all?"
On lap 30 Russell's car stopped with a technical failure. He was leading the race. Virtual Safety Car.
Antonelli, Verstappen, Hamilton, Leclerc and Hadjar all stopped on lap 31; Colapinto, Gasly, Lawson, Sainz and Bearman had come in the lap before, according to F1.com. The front had got 30 laps out of the soft and their only planned stop under a neutralisation. And they fitted medium, not hard.
That is the race's most important strategic detail. Before the race Pirelli said soft to hard. On lap 31 there were 37 laps left, degradation was zero, the medium was easier to warm – and the hard was almost a second slower. The simulator puts a number on it: had Antonelli taken the hard under the VSC he would still have won, but 14 seconds slower. Pirelli's pre-race optimum was worse: medium to hard with a stop in the window on lap 22 would have given Antonelli P3, 37 seconds behind. For Verstappen P4, 45 seconds. Following the theoretically fastest strategy would have been the most expensive decision in the race.
The VSC itself was worth about ten seconds: a green stop for Hamilton on lap 25 would have cost eleven seconds and P3 instead of P2. And patience would have been free even without a neutralisation: Antonelli could have stopped as late as lap 40 and still won.
After Russell's retirement Hamilton was in the fight behind Antonelli and Verstappen on the same strategy as both. Then he hunted: 3.7 seconds behind Verstappen on lap 45, 2.6 on lap 50, 0.7 on lap 60. On lap 62 he went round the outside into Turn 1, according to F1.com. No tyre difference – both on mediums from lap 31 with zero slope – just pace: 74.6–75.1 against 74.8–75.6 over the last ten laps. Antonelli won by 10.8 seconds, Hamilton 0.5 ahead of Verstappen, Leclerc 44 seconds back.
Colapinto and Gasly started on the medium, ran 30 laps and switched to the hard – Pirelli's medium to hard, stretched thanks to the non-existent degradation. Colapinto finished P6, Gasly P8, and Pirelli singled out Alpine as proof that the theoretically fastest strategy worked, according to press.pirelli.com.
The data disagrees. Alpine's stops were also under the VSC, not green, and the hard was the slowest tyre of the day: Gasly's base pace on the hard was the same as on the medium despite 30 laps fresher rubber, Colapinto's 0.4 seconds worse. Had Gasly taken the soft on lap 30 he would have finished P6, Colapinto P5. What earned Alpine the points was the long first stint and the neutralisation. The hard cost them a place each. Everyone from P5 down was lapped, incidentally.
The pit-stop table lies about three drivers. Piastri made three stops: intermediates to medium on lap 1, a new front wing and medium on lap 12 after the collision with Albon at the hairpin, and a stop under the second VSC to serve his ten-second penalty for the collision as cheaply as possible while taking softs for the final stint, according to McLaren. Hadjar made one strategic stop – soft to medium under the VSC – and two penalty visits: ten seconds for changing direction more than once against Leclerc, served under the second VSC, and then a stop-and-go for ignoring yellow flags, according to F1.com. With only the first stop he would have finished P4. The second VSC came on the leader's lap 53, for marshals at Turn 12, and was over a lap later.
Ocon is the interesting case. Haas brought him in as planned on lap 16, soft to medium, long before anyone else. It looks like a mistake in a race where the soft lasted all the way to lap 30. But the data says otherwise: Ocon's soft laps 8–15 were 79.1–79.7, while Bearman, Hülkenberg and Bortoleto on equally old softs ran 77.4–78.5. He was 1–1.5 seconds per lap slower than everyone else on the same tyre, in a car he himself described as difficult in pace, balance and braking after big set-up changes, according to F1.com. On the medium he ran 78.3–78.7 – faster than on the soft. The stop was an attempt to find pace, and it found pace. A single stop on lap 30 would have saved him around twenty seconds and given exactly the same place, P14, two laps down.
Judged on the information available when the decision was made:
- Pirelli – one stop: right. Medium to hard as fastest: wrong by 37 seconds.
- Mercedes, Ferrari, Red Bull – soft start in the cold: right, and free in pace.
- The front under the VSC – medium instead of hard: the race's best decision, worth 14 seconds.
- Alpine – medium to hard: right stint, wrong tyre.
- Red Bull/Hadjar – a good strategic stop buried under two penalties.
- Haas/Ocon – early switch to medium: reasonable for a car that did not work on the soft, cost time but no place.
- McLaren, Audi, Cadillac, Sainz – intermediates: a gamble that two formation laps had made impossible before the start.
After five races the picture of 2026 is clearer: tyre life has rarely been the constraint. Strategy is decided by track position, neutralisations, warm-up and the ability to keep the pit window open. Canada is the clearest example yet – and the first where Pirelli's fastest strategy would have been an outright mistake.
Sources: F1.com (preview, Pirelli comments, race report, race control log, stewards' decisions), press.pirelli.com, McLaren (Piastri's stops), FastF1 data for lap times, stint slopes, pit times and running order per lap. Simulator pit loss is set to 20.5 s under green (the cleanest measured green stops) and 10.2 s under the VSC. Lap numbers refer to the lap on which the driver entered the pits; lapped drivers run one or two laps behind the leader's count.
Simulate
Change one driver's pit stops and let everyone else run exactly as they did. The altered driver is modelled with his own pace per compound from the race, degradation, fuel, traffic and the VSC discount – cars that get stuck behind him lose time.