F1 tyre strategy: the two-compound rule
How F1 tyre strategy works in dry and wet races, from the two-compound rule to one-stop and two-stop plans, plus undercut and overcut calls.
In a dry Formula 1 race, drivers must use at least two different dry tyre compounds, and that rule shapes every major strategy call from pit stops to weather changes. It is one of the reasons teams balance outright pace, tyre life and track position rather than simply running the fastest tyre for the full distance.
Two-compound rule
In a race declared dry, each driver must use at least two different slick compounds if they finish and are classified. That long-standing sporting rule means a no-stop run on one set of dry tyres is not a legal strategy in normal dry conditions. The exact compound names available at a given event can vary by season and supplier selection, but the principle is stable: two different dry compounds must be used.
If the race is run in wet conditions and drivers use intermediates or full wet tyres, that dry-race requirement does not apply in the same way. Once weather changes the picture, teams can switch to the tyre that best matches the track surface rather than trying to satisfy the slick-compound rule. That is why a race that starts dry can have one strategic shape, then change completely if rain arrives.
One-stop vs two-stop
A one-stop strategy usually aims to minimise time lost in the pit lane and protect track position. The trade-off is that each stint is longer, so the driver may need to manage tyre wear, overheating or performance drop-off more carefully. If the tyres hold on well enough, one stop can beat a theoretically faster plan simply because passing on track is difficult.
A two-stop strategy adds another pit visit, which costs time, but it can give the driver more laps on fresher tyres. That often means stronger pace, more attacking options and less need to conserve the rubber. Teams choose between one stop and two stops by weighing pit-lane time loss against the lap-time gain from newer tyres, while also considering traffic, overtaking difficulty and the chance of a safety car changing the calculation.
Weather and tyre calls
Weather is the quickest way to overturn a pre-race plan. A team may begin with a one-stop dry strategy, then abandon it if light rain makes slicks unworkable or if a drying track makes intermediates too slow. The timing of that switch matters as much as the tyre choice itself, because stopping one lap too early or too late can cost several positions.
Intermediates are used when the track is damp or drying and there is not enough standing water for full wets. Full wet tyres are for heavier rain and more water on the circuit. In mixed conditions, teams are judging grip sector by sector, not just by a single lap time, and they must decide whether to react immediately, wait for clearer conditions, or split strategies across their two cars.
Undercut and overcut
The undercut is a move where a driver pits earlier than a rival and uses fresher tyres to gain enough lap time to come out ahead once that rival makes their stop. It works best when new tyres offer a clear pace advantage and the driver can use clean air after the pit stop. Teams often try it when they are stuck behind a slower car and need track position more than a longer first stint.
The overcut is the opposite idea: staying out longer and trying to gain time while the rival has already stopped. That can work if the older tyres are still performing, if the rival rejoins in traffic, or if track conditions improve for the later stop. Both tactics are really about the same goal in F1 tyre strategy: using pit-stop timing and tyre performance to gain track position when passing on the circuit is harder than passing in the strategy phase.