Tyre analysis: Wet-weather F1 thriller at Zandvoort

The race at Circuit Zandvoort was chaotic due to two huge rain showers, and this made for a lot of spectacleF1Technical's senior writer Balázs Szabó picks out some key strategy lessons from Sunday's Zandvoort race.

Despite challenging conditions and a lengthy stoppage, double world champion nobody was able to stop Max Verstappen from taking his third consecutive Dutch Grand Prix victory, at the same time equalling the record for nine straight wins in a season, previously set by Sebastian Vettel in 2013, also at the wheel of a Red Bull. This was Verstappen’s 46th career win, bringing his total number of podium finishes to 90.

In the eyes of the spectators, the rain was perfectly timed as drivers started the race on Pirelli's dry-weather soft tyres (Hamilton started on the mediums), but they were forced to pit for intermediate tyres as a downpour arrived just in time when the field approached the final sector on the opening lap.

However, some brave drivers were reluctant to pit for intermediates. The Mercedes duo of Lewis Hamilton and George Russell, McLaren's Lando Norris and Aston Martin's Lance Stroll waited until Lap 3 or 4 to dive into the pit which meant they they all dropped down the order as they lost over twenty seconds per lap compared to their rivals who switched to intermediates early on. Considering that a pit stop results in a loss of 22s at Zandvoort, the lost time due to the "extra" stop could be regained within a single lap.

While Hamilton, Russell, Norris and Stroll made a clear strategy mistake, there were several others who fell into the trap even more: the Williams duo of Logan Sargeant and Alexander Albon, Nico Hulkenberg, Valtteri Bottas and Oscar Piastri opted to stay out, banking on the rain not lasting long. Indeed, after about ten laps, the track was again suitable for slicks.

The track dried up quickly, but taking McLaren's Piastri as an example, he lost 61 seconds to Max Verstappen between Laps 4 and 7 on his slick tyres, meaning that even a much later switch to intermediates (compared to the early stoppers) could have lessened the impact of the strategy mistake. In fact, Lap 8 was the first when the soft compound was faster again than the intermediates.

It meant that in the space of 12 laps everyone was back on dry tyres. In these very cool conditions, the Soft was clearly the best compound and was used for as long as possible, as can be seen from the fact that AlphaTauri's Yuki Tsunoda did 50 laps with one set and Williams racer Alex Albon 44. Only one driver, Russell, opted for the white-banded hard tyre, finding himself down the back end of the pack after the Safety Car came out following Sargeant going off track. The Mercedes driver would probably have finished the race on that set of C1s if the rain had not decided to once again shake things up, but he constantly lost performance towards the end of his stint on the hard compound.

Once again, all the drivers began to pit and with the rain really coming down, some even opted to fit the extreme wet, Ocon being the first to do this followed by the two Red Bull drivers. The race was red flagged after Zhou went off, so the question as to how these tyres would have performed in these conditions went unanswered. In the closing stages after the restart, Race Director Niels Wittich decided to mandate the use of the intermediate tyres for the last part of the race.

With the conditions constantly changing during the long race, race winner Verstappen needed five pit stops en route to his third successful victory on home soil. While many think that this is might be record, the Dutchman himself has already won an F1 race with five pit stops.

At the 2019 German Grand Prix, the rain wreaked havoc at the Hockenheimring as teams desperately changed strategies. With the track drying up after the start and sudden downpours in later phases of the race, drivers were forced to change onto slick, wet or intermediate tyres. In the end, Verstappen came out victorious while conducting five pit stops.

However, this is not the absolute record as Jenson Button completed six pit stops at the 2011 Canadian Grand Prix en route to a sensational victory. The Briton had a difficult start to his race, making contact with his team-mate Lewis Hamilton and then Ferrari driver Fernando Alonso and falling back to the last position. He then made his way up through the field and overtook Sebastian Vettel on the last tour of the Montreal race. The 2009 F1 champion conducted a total of six pit stops of which one was a drive-through penalty.

Pirelli's Motorsport Director Mario Isola said: “It was a very spectacular race, with several changes in the weather which made life difficult for the teams when it came to deciding on which tyre to use and when to pit. From a purely technical point of view, apart from the literally colourful sight of having all five our tyre colours being used, two aspects are worth highlighting. As expected over the course of the weekend, the cooler temperatures favoured the use of the Softs, clearly the best tyre in the dry, even coping well in wet conditions, as demonstrated by the drivers who chose not to pit in the opening laps when it started to rain.

"The compound most affected was the Hard, but the long stint from Russell, who would probably have run to the chequered flag if the rain had not returned, demonstrated that this tyre was not totally unsuited to the conditions. The second point to underline concerns the Intermediate, which once again proved to be competitive with either a little or a lot of water on the track.

"Finally, there are various people I wish to congratulate: Max Verstappen for his ninth consecutive win, the Zandvoort spectators who once again put on an amazing show in the grandstands, their enthusiasm so contagious despite the bad weather, Fernando Alonso back on the podium, as he had been doing regularly at the start of the season, at one point even looking to challenge for the win and to Pierre Gasly who produced a really great result.”