How Formula 1 teams decide when to pit, which compound to use and how to execute an undercut or overcut.
Every Formula 1 race requires drivers to use at least two different dry tyre compounds. This mandatory two-compound rule forces every team to make at least one pit stop during a dry race, turning the pit lane into a critical strategic battleground. The decision of when to stop, which compound to switch to and how many stops to make can be the single biggest factor separating victory from defeat.
In 2026, Pirelli supplies five dry-weather slick compounds numbered C1 through C5. Each race weekend Pirelli nominates three consecutive compounds from this range — the softest option (S), a medium compound (M) and the hardest compound (H). The softest tyre delivers more peak grip but wears out faster. The hardest tyre lasts longer but provides less grip and a slower baseline pace.
Teams use sophisticated predictive models to estimate the precise lap at which each compound will lose competitive performance. Once a tyre passes its optimal window, degradation accelerates rapidly — often referred to as "going off a cliff." Pitting at exactly the right moment, before or just as the tyre deteriorates, is the core objective of race strategy.
The undercut is one of the most frequently used strategic weapons in Formula 1. To execute an undercut, a driver pits one to three laps before their direct rival. The aim is to fit fresh tyres first, set fast lap times on new rubber, and emerge from the pit lane ahead of the rival after they make their own stop.
For an undercut to work, the pace advantage of fresh tyres must be large enough to overcome the time lost in the pit lane — typically 20 to 26 seconds depending on the circuit and the pit lane layout. If a new set of soft tyres is 1.5 seconds per lap faster than worn medium tyres, the driver needs roughly 14 to 17 laps to recover a 22-second pit stop deficit. In practice, the undercut is most effective when the attacking driver is within two seconds of the car ahead and the tyre delta is at least 0.8 to 1.0 seconds per lap.
A successful undercut requires precise timing by the pit wall. If the driver pits too early, the gap to the rival is too large to recover with pace alone. If they pit too late, the rival has already extended their own advantage to the point where even fresh tyres cannot make up the lost ground.
In 2026, the new active aerodynamics system adds an extra layer to undercut calculations. A driver on fresh tyres can deploy full ERS boost in aero zones, amplifying the pace advantage of new rubber. This makes early-lap tyre advantage even more pronounced than it was under the DRS era.
The overcut is the inverse of the undercut. Rather than pitting before a rival, the overcut involves staying out on track while the rival pits. The driver who remains out benefits from clear air — no traffic, no dirty air — and can often push their tyres harder and set competitive lap times while the rival exits the pit lane slowly on their out-lap.
Overcuts are most effective when tyre degradation is low, the track position advantage is large, and the rival's fresh tyres do not provide a significant lap time advantage. Street circuits like Monaco are classic overcut venues because overtaking is nearly impossible even with a tyre advantage, making track position paramount.
A successful overcut requires the driver to manage their tyres carefully in the laps before and during the rival's stop, preserving enough rubber to run fast lap times on older compounds. The strategy also depends heavily on traffic — if the driver on older tyres gets caught behind slower cars, the overcut advantage evaporates quickly.
Teams often discover overcut opportunities reactively. If a Safety Car deploys just after a rival pits, the driver who stayed out can pit under the Safety Car and receive a drastically reduced time penalty, effectively gaining the position for free.
The strategic split between one-stop and two-stop races is one of the most fundamental decisions teams make before lights out. A one-stop strategy minimises total time lost in the pit lane but requires at least one stint on a slower, harder compound. A two-stop strategy allows the driver to run softer, faster rubber for more of the race but introduces an additional pit stop and the associated time loss and track position risk.
The optimal pit window for each compound changes race by race depending on circuit characteristics, ambient temperature and tyre degradation rates. As a general reference, the 2026 Pirelli compounds follow these approximate stint windows under normal racing conditions:
Fastest compound but shortest lifespan. Cliff arrives rapidly after the performance window closes. Best used as a qualifying simulation or short final stint.
The most versatile race compound in 2026. Competitive pace with manageable degradation. Often forms the backbone of a one-stop strategy.
Lower peak grip but exceptional durability. Enables long stints and one-stop strategies on high-degradation circuits when managed correctly.
PITWALL lets you set compound, pit timing and ERS plan, then simulate the full race against 19 AI rivals across all 23 circuits.