MONTE CARLO, Monaco -- On the face of it, Monaco Grand Prix strategy is simple: A one-stop, with a switch from the soft compound to the hard roughly a quarter of the way into the race, is the most risk-averse and fastest way to the chequered flag. However, the high chance of a Safety Car, and the difficulties some drivers have had generating heat in their tyres this weekend, means strategists must remain flexible to take advantage of any opportunities of moving up the field during the 78 laps.
Overtaking is nearly impossible around the tight street circuit, but crashes frequently happen. As a result, strategists are constantly on the lookout for how a Safety Car -- or in extreme cases a red flag -- could change the race on any given lap.
"Safety Cars are a very common occurrence here and in the last 20 years we have had 18 Safety Cars, so we are quite certain that at some point of the race it is very likely we will have a Safety Car," Ferrari head strategist Inaki Rueda explains.
"What are the implications of a Safety Car? First of all, there is the pit stop loss. Under normal racing circumstances we have to pit stop for the tyres and we normally lose around 20 seconds. When the Safety Car comes out everyone needs to go at reduced speed, around 60 percent slower than what we usually do, and what this means is that the gaps actually get bigger, so instead of losing 20 seconds when we stop, we only lose 12 seconds. This is very important because here it is impossible to overtake, but if you manage to pit when there is a Safety Car and others stopped when there was no Safety Car you gain eight seconds on them, so you potentially gain places.
"The other thing is tyre warm-up. You want to make sure that if there is a late Safety Car here -- unlike in Spain where nearly everybody stopped -- here, you might not make those positions back, so you need to make sure that if there is a late Safety Car you ask 'are my car's tyres OK to make it to the end of the race if I don't stop?' Depending on the compound you have, the temperature of the tyres, the state of the track, you need to make sure the compound you have, or the compound you are going to put on, is the correct one. That is separate to the normal race strategy.
"The other big uncertainty is red flags. It is not unheard of here, and we have had two red flags in the last 10 years. The biggest implication is that if we have a red flag we do not have to pit stop. Our regulations do not tell us that we have to pit stop, they just tell us that we need to run two compounds and we can change compound under the red flag. So if we get a red flag we don't need to pit.
"Again, if you get very lucky and you have not stopped yet you are very lucky and you do not need to stop again."
Without a Safety Car, the strategists have to turn their attention to more marginal gains. At most racetracks the "undercut" -- when a driver pits earlier than his rivals for fresh tyres and gains positions by lapping faster -- is the most powerful weapon in the strategists armoury, but in Monaco the "overcut" comes into play.
"At most tracks we speak about undercuts, which is the process by which the car that stops first, from behind, gains a position to the car in front," Rueda adds. "In very few tracks where there are tyre warm-up issues, like here or Baku for example, you have the opposite phenomena which is called an overcut."
Because the cars put such little energy into the tyres in Monaco's relatively slow corners, it can take two or three laps for fresh rubber to get up to temperature and offer maximum grip (especially with the medium and hard compounds). As a result, a driver that makes an early stop can actually lose time on fresh tyres as he waits for the compound to come into its operating window. That offers an opportunity for rivals to stay on track, continue for a handful of laps at a faster pace on their much older tyres, and then pit in the hope the time gained brings them back on track ahead.
Sebastian Vettel used this strategy to beat teammate Kimi Raikkonen in 2017, but this year's Pirelli tyres are even harder to get up to temperature than the last two years making the "overcut" even more powerful. This factor may mean drivers save their tyres at the start of the race in order to extend their first stint much longer than Pirelli recommends in order to make sure they do not lose out by being the first to stop.