Out-Lap Versus In-Lap: How Pit Timing Decides Track Position

The Mechanism Behind Pit-Stop Passes

When two cars race within pit-stop range of each other, overtaking on track is not the only way to gain a place. Strategists often rely on timing the pit stop itself to leapfrog a competitor. The tactical choice between an F1 undercut and overcut hinges on balancing the pace of a driver on freshly fitted rubber against the pace of a driver remaining on used tyres.

In an undercut attempt, the trailing or rival car pits first to attack on an aggressive out-lap with fresh tyres. If the new compound grips immediately and track air is clear, that rapid out-lap can overcome the gap while the leader stays out to complete an in-lap on degrading rubber. Formula 1 reported an extreme event-specific example from the 2019 Singapore Grand Prix, where Sebastian Vettel pitted on Lap 19 onto new hard tyres and recorded a lap roughly four seconds quicker than Charles Leclerc, who remained on older rubber before pitting a lap later. While four seconds represents a single historical data point rather than a universal baseline, it illustrates how rapidly a fresh-tyre delta can reverse track order.

When Staying Out Trumps Pitting First

Pitting first does not guarantee an advantage. An overcut relies on the opposite dynamic: a driver stays on track after an opponent pits, aiming to deliver a fast in-lap while the stopped rival struggles through warm-up delays or rejoins behind slower traffic.

Tyre warm-up characteristics and tyre wear heavily influence whether extending a stint succeeds. During the 2021 Monaco Grand Prix, low degradation paired with slow new-tyre warm-up shifted the balance toward staying out. Lewis Hamilton attempted an undercut against Pierre Gasly that failed when new hard tyres took time to reach operating window, while Sergio Perez and Sebastian Vettel utilised longer opening stints to advance. Extending a stint simply to 'go long' is distinct from a targeted overcut, as going long accepts a temporary loss of track position in exchange for a tyre offset later in the Grand Prix.

Strategic Variables and Pit-Lane Risks

Executing either tactic requires evaluating several variables beyond raw tyre life. Even a well-timed stop can unravel if a car exits into congested traffic, suffers an extended pit-lane transit loss, or encounters neutralisation periods like safety cars.

At the 2021 United States Grand Prix in Austin, Red Bull demonstrated the timing disparity inherent in these calls when Max Verstappen stopped on Laps 10 and 29, compared to Lewis Hamilton stopping on Laps 13 and 37. Mercedes team principal Toto Wolff described the opening stop—three laps earlier than Hamilton—as an aggressive undercut. Both approaches reflect strategic intent rather than guaranteed outcomes, with track layout, degradation rates, warm-up windows, and track traffic ultimately determining which phase of the pit cycle holds the advantage.

Official reference: Monaco 2021 strategy analysis.