Undercut

The undercut is a strategic manoeuvre in Formula 1 where a driver pits earlier than a rival, gains the advantage of fresh tyres, and uses the resulting faster lap times to emerge ahead of the rival when they eventually pit. The undercut works because fresh tyres are significantly faster than worn tyres — a driver on new tyres can lap 1-2 seconds faster per lap. If the time gained through faster laps exceeds the time lost in the pit lane, the driver who pitted first will emerge ahead. The undercut is most effective when the tyre performance delta is large (i.e., when tyres are very worn) and when the pit lane time loss is relatively small. Teams use sophisticated computer models to calculate the optimal timing for undercuts.

The undercut became a central strategic concept in F1 following the ban on refuelling in 2010, which made tyre strategy the primary strategic variable. The development of Pirelli's high-degradation tyres from 2011 onwards made the undercut even more powerful, as the performance delta between fresh and worn tyres was very large.