The undercut is one of Formula 1's most powerful strategic tools — a sequence of events triggered by a pit stop that can transfer a race position in the space of two or three laps without the overtaking driver ever passing the car on track. Understanding how and why it works reveals the depth of strategic thinking that underpins every modern grand prix.
The undercut works as follows: Car A is running just ahead of Car B. Both cars are on worn tyres. Car B pits one lap before Car A and fits fresh tyres. On its out-lap, Car B can now lap significantly faster than Car A — which is still on degraded rubber. If Car B's out-lap gain is greater than the time spent in the pit lane, when Car A eventually pits, Car B will emerge ahead.
The key conditions required for a successful undercut are: a significant pace difference between fresh and worn tyres, a circuit where fresh tyres create a meaningful lap time advantage on the out-lap, and the team ahead not reacting with an immediate "cover" stop of their own.
Teams defend against the undercut by "covering" the stop — reacting immediately when they see a rival pit. This forces the undercut attacker to gain their time advantage purely from tyre pace difference, and if the ahead team reacts within one lap, the time in the pit lane often negates the advantage. The overcut — staying out and gaining track position as others pit onto cooler tyres — is the counter-strategy, and choosing between them correctly in real time separates the best strategists in the sport.