Pirelli brings three dry compounds to every Grand Prix, labelled soft (red), medium (yellow) and hard (white) for that weekend, plus intermediate (green) and full wet (blue) tyres for rain. Softer rubber is faster over one lap but wears and overheats sooner. Almost every race strategy is a trade between those two facts. The tyre strategy tab draws each driver’s stints as coloured bars across the race distance.
The two-compound rule
In a dry race each driver must use at least two different dry compounds, which forces at least one pit stop. If the race is declared wet, or a driver runs intermediate or wet tyres at any point, the rule no longer applies. That is why a mid-race shower can scramble the order.
What a pit stop costs
The stationary time of a good stop is two to three seconds, but the real cost is the whole trip through the pit lane at the speed limit compared with staying on track. Depending on the circuit this is usually between 18 and 25 seconds. A team will only stop again if fresh tyres can win back more than that over the rest of the race.
Undercut and overcut
The undercut is pitting before the car ahead. On new tyres your first few laps are much quicker than your rival’s laps on worn tyres, so when they stop a lap or two later you may come out in front. The undercut is strongest when new tyres are much quicker than old ones and the tyres warm up quickly.
The overcut is the opposite: stay out while your rival pits, and use the clear track to set fast laps before you stop. It works when fresh tyres take several laps to reach temperature, or when the rival pits into traffic.
Safety cars change everything
Under a safety car or virtual safety car the field slows, so a pit stop costs roughly half as much time. Teams often pit everyone they can the moment one is called. On the stint chart, you will see many drivers’ bars change colour on the same lap. Check the race control tab for the matching message.
Reading the stint chart
- Long first stints on hard tyres usually mean a one-stop plan built around track position.
- Short stints on softs at the end usually follow a late safety car, when a cheap stop for fresh tyres was too good to turn down.
- Several drivers switching to green or blue within a lap or two marks the arrival of rain.