Here’s all you need to know about F1’s mandatory pitstops at Monaco GP

“This has nothing to do with racing,” concluded Max Verstappen after last year’s Monaco Grand Prix. It fits a pattern: Saturdays are spectacular in the principality, but Sundays tend to offer limited to almost no action. This is obviously due to overtaking with today’s large F1 cars being virtually impossible around the streets of Monte Carlo.

In the 2024 race, an early red flag compounded the situation. It gave all drivers a free tyre change, after which everyone could run to the end without further stops, due to Monaco’s low tyre degradation. Normally, these pitstops are the only opportunity to shake things up in Monaco — but even that aspect disappeared in 2024.

How does the new Monaco rule work?

To avoid a repeat of that scenario, changes have been made. Layout tweaks are difficult in Monaco’s tight streets, so a different approach was needed. It resulted in a special Monaco rule, commonly referred to as a two-pitstop rule.

However, that wording is not entirely accurate. As confirmed by the FIA, the rule does not necessarily mean that teams are required to make two pitstops. It states that drivers must use three different sets of tyres, and that’s an important difference — especially if there’s another red flag like last year. During a regular race, teams can comply with the tyre regulations by switching compounds under red flag conditions, meaning they do not need to stop again. The same rule applies during a red flag in this year’s Monaco Grand Prix. So if teams switch compounds during the stoppage, it still counts as a free pitstop. In that case, only one regular stop would be required.

That’s a potential risk to the whole plan: if there’s an early red flag and all teams switch compounds, the rest of the race could turn into a typical Monaco one-stopper — making all the paddock talks about this new rule pointless. However, even in that case it would still prevent a repeat of last year, which was one of the primary goals behind the change.

It’s worth noting that the FIA has already closed several potential loopholes. Pitstops at the end of the formation lap don’t count for example, after some teams asked about that. A team cannot dive into the pits before the race officially starts in order to get one stop out of the way. The FIA has clarified that only the tyres a driver starts the race with (either from the grid or pitlane) will count as a first set for the race.

Why aren’t teams required to use all three compounds?

With the rule requiring three sets of tyres, one might wonder why the FIA and Pirelli did not require the use of all three compounds instead of just two. It would make strategy even more complex for teams and potentially more interesting for fans. But as tyre wear in Monaco is extremely low, Pirelli believes it wouldn’t make much of a difference.

“No, I don’t think it would have changed too much. We have seen that some teams already used one set of the hard compound in practice, so basically they are not keeping the hards because they are scared about the mileage the tyres can do,” Pirelli’s Simone Berra replied when asked by Motorsport.com. “Also the C6 could be fine on a pretty long stint, we’re speaking about 20 or 30 laps, the C6 can do that.”

That said, none of the frontrunning drivers from McLaren, Ferrari and Red Bull have a fresh set of softs left for the race, just three or four used sets. Apart from Lewis Hamilton (whose medium tyres were used for two laps in qualifying), all drivers from the aforementioned teams still have a new set of mediums. The McLarens are the only frontrunners with two new sets of hard tyres left; Verstappen and Leclerc each have one new set of white-walled tyres.

What are the most likely scenarios for teams and drivers?

The key question, of course, is: what all of this will mean on track? First, many more variables and, therefore, more strategic headaches for all teams. “There’s a group of engineers saying, why has this been done to us? But we’re in the entertainment industry”, Aston Martin CEO Any Cowell commented. “It will be more entertaining because there will be 10 teams approaching it slightly differently.”

McLaren team principal Andrea Stella smiled during Friday’s tech session: “As the race weekend came closer and our strategists started to think about the implications, the implications turned out to be much bigger than what we thought in the F1 Commission. We are still scratching our head in terms of considering all the options.”

The special Monaco rule is interesting in two ways. First, teams outside the points may choose to gamble — at least with one car. In theory, this could mean completing both pitstops in the opening laps, but that seems unlikely. The explanation is simple: if the safety car comes out after that, anyone who hasn’t yet pitted will get a free stop and the early gamblers wil lose out.

“I heard some comments or questions about the possibility to have cars doing both stops at the beginning of the race. It’s not forbidden, obviously, so it’s something that any driver and any team could plan. But in my opinion it’s not really an option,” Pirelli’s Mario Isola agrees.

“Because here, safety car, virtual safety car and red flag are quite common. And if you use both the pitstops at the beginning and then you have a safety car, you damage your race, basically. Because you pay the full time for the pitstop and you don’t get any advantage of a safety car or a virtual safety car.”

Instead, Isola points to another interesting scenario if there’s a long safety car period — like the eight laps in Imola. “Then everyone will come in two times in two laps. It makes sense, because you don’t have any more obligation for the rest of the race. But the problem is that 20 cars in this pitlane are not really… I’m not sure that they have enough space.”

Besides the gambling possibilities at the back, the rule also has implications at the front. Two pitstops usually mean two undercut chances, but that aspect is much harder to predict. As Helmut Marko pointed out, Lando Norris holds the keys in that regard. The rest of the field will have to react to McLaren’s strategy. “Let’s see how the race is with Norris, is he going quick or is he cruising? Last year they were driving four to to five seconds slower, so they were nearly slower than a Formula 2 car. As we are not in the front, we are not the ones who can influence or dictate that.”

If Norris holds the lead at the start, he has strategic control. If he drives slowly, the field remains bunched up, making it hard for others to try an undercut since they’d rejoin in traffic. Norris can play around with this, according to Marko. “We saw in F2 that [Arvid] Lindblad was three seconds faster than the guy in front, but there was still no way to overtake. And a Formula 2 car is a bit smaller than a Formula 1 car, so even if you are five seconds quicker you can’t overtake here.”

In other words, if McLaren leads into Turn 1, it is in control and the other teams must adapt. It makes strategy extremely hard to predict — even for teams themselves. “It might be a lottery,” Max Verstappen acknowledges. “It might be positive for you or negative, it’s impossible to know at the moment. But it definitely makes it more complicated to get it right. You have to wait and see what happens tomorrow, you just need to be prepared for any kind of scenario.”

Those last words are the perfect summary for both teams and drivers: there are so many possible scenarios that at least part of it will come down to improvisation and on-the-spot decision-making — reacting effectively to what unfolds on track and what Norris does. Whoever handles this best on Sunday afternoon could hit the jackpot in Monaco.

Photos from Monaco GP – Practice & Qualifying