Strategy in a Formula 1 race

A Formula 1 race is rarely won by whoever is fastest over a single lap, but by whoever puts together the shortest total time over 50–70 laps. That time is governed by three things pulling in different directions: the tyres get slower with every lap, the car gets faster as fuel burns off, and every pit stop costs twenty seconds or more. This page explains how the optimizer does the maths – and what the 2026 regulations add.

1. Why you pit at all

A tyre loses time on every lap it is used. The loss is often close to linear across a stint – a few hundredths per lap on a hard tyre, perhaps a tenth on a soft – and it is called degradation, α. After twenty laps on a tyre losing 0.07 s/lap you are running 1.4 s slower than on a fresh set. A pit stop, by contrast, costs a fixed amount: the time in the pit lane under the speed limit plus braking in and accelerating out, typically 18–25 s depending on the circuit. The question behind every strategy is therefore simple to state: on which lap does the accumulated tyre loss exceed the cost of a stop?

2. The compounds

Pirelli brings three dry compounds to every event: soft (fastest, wears quickest), medium and hard (slowest per lap, lasts longest). The difference in base pace is often 0.3–0.8 s per lap between steps, and the difference in degradation larger still. In a dry race at least two different compounds must be used – which is why one stop is mandatory and why the order (e.g. medium → hard or hard → medium) is a strategy call in itself.

Pirelli's nominations: C1–C5

"Soft", "medium" and "hard" are not the same rubber at every circuit. Pirelli has a range of homologated compounds from C1 (hardest, most durable) to C5. Ahead of each weekend three steps are chosen from the range – usually adjacent ones – and they receive the weekend's colours. At a circuit with extreme lateral loads and abrasive asphalt (Silverstone, Suzuka, Barcelona, Zandvoort) C1/C2/C3 are nominated; at a low-energy circuit like Monaco, C3/C4/C5. The same physical tyre, C3, can therefore be the weekend's soft at Silverstone and the weekend's hard in Monaco.

That matters for the model: when α is taken from previous races at the same circuit, the comparison has to be made per C-code, not per colour – otherwise the wrong tyres are compared as soon as Pirelli shifts a step between seasons. The timing data does not contain the C-code, so the nominations are entered by hand from Pirelli's official "Tyre Compound Choices" and the FIA Event Notes. The weekend's nomination is shown on the front page next to the model values.

3. The model behind the curve

The optimizer estimates two numbers per compound from the practice sessions (mainly FP2 and FP3, where the teams do long runs on race fuel): the base pace t₀ at zero wear and the degradation α. Only genuine long runs are used – consecutive laps with no flags, in-laps/out-laps or traffic. The lap time on lap k of a stint then becomes:

where β_fuel ≈ 0.035 s/lap is the gain from a lighter car. The race is simulated lap by lap for every conceivable pit lap and every order of compounds, and the curve on the front page shows the time lost against the best alternative.

4. The pit window

There is rarely one right lap. Around the optimum the curve is often flat: stopping three laps earlier or later might cost half a second. That interval – where the loss is under a second – is the pit window, and it is where the tactical decisions are made:

• Undercut – stop before your rival and use the fresh tyres to go fast enough that you emerge ahead when they stop. Works when new tyres deliver a big gain straight away.
• Overcut – stop later, and exploit clear track while your rival is stuck in traffic on their new tyres.
• Traffic – emerging behind a slower car can cost more than the entire width of the window. That is why the teams work out which lap gives "clean air".

5. Fuel and track evolution

The car starts with up to around 100 kg of fuel and gets roughly 0.03–0.04 s faster for every lap burned. At the same time, rubber is laid down on the track so that grip increases over the weekend. In the practice sessions that effect is a source of error: it masks part of the degradation and makes α slightly too optimistic. The optimizer compensates for fuel explicitly; track evolution is one of the things backtesting against real races is meant to calibrate.

6. Safety Car and VSC – the cheap stop

A pit stop costs time because the car crawls through the pit lane while the rivals are flat out. Under the Virtual Safety Car (VSC) everyone must hold a delta pace that is 30–40 % slower, and under the Safety Car (SC) the field trundles behind a car at a far lower speed. The pit lane is as slow as ever – but the difference against the field shrinks, and that difference is the cost.

A stop under green typically costs 20–25 s against the field. Under VSC you save in the order of 5–8 s of that, under SC 8–12 s – and behind the Safety Car the field bunches up as well, so what you lost in time you often get back in position.

That is why the strategy engineers watch two things at once: where the pit window sits on paper, and how much of it has already been used up. A VSC on lap 15 with a window opening on lap 20 is a hard call – the stop is cheap, but the tyres then have to last six laps longer than planned at the end of the race. A VSC on lap 22 is easy: box. The optimizer shows the weekend's measured pit loss under green, VSC and SC next to the model values; the curve itself assumes a green race, because the Safety Car is the chance event you plan your reaction to, not the basis you plan from.

Where the values come from

Backtesting against the 2026 races showed that practice long runs overestimate degradation by a factor of two to eight: they are short, driven on the limit and capture the tyre's steep initial phase, whereas a race stint is managed to a target pace. So α and the longest realistic stint length per compound are taken first from previous races at the same circuit (same C-code where known), second from the season median, and only as a last resort from the practice session. The practice session contributes the base pace and a warning if something departs from the history. Every value on the front page carries its source with it.

7. What 2026 adds: energy as a third variable

Up to and including 2025 it was essentially enough to weigh tyres against fuel. From 2026 the power split between combustion engine and electric motor is close to 50/50: the combustion engine delivers around 400 kW and the MGU-K electric motor 350 kW. The MGU-H – which used to recover energy from the exhaust – is gone, so all electrical energy must be harvested under braking. That turns the battery's charge level, the State of Charge (SoC), into a strategic resource.

Clipping

The battery holds in the order of 4 MJ. At full electrical power it is empty in just over ten seconds – shorter than a long straight at Monza, Spa or Baku. When the energy runs out the electric motor clips its output and the car loses speed at the end of the straight. So the driver cannot go "flat out" every lap; the energy has to be budgeted with lift and coast and harvesting laps.

Active aerodynamics

DRS is replaced by two aero modes: Z-mode with high downforce in the corners and X-mode with low drag on the straights, where the front and rear wings flatten. Less drag means less energy consumption and less vertical load on the straights, but the tyres are instead loaded harder in the transition back to Z-mode ahead of the heavy braking zones.

Override mode

The overtaking aid is no longer aerodynamic. A car within one second behind instead gets access to an override mode with extended electric boost at high speed, while the leading car's electric assistance tapers off towards top speed. Running close to a rival therefore gives a power advantage on the straights – but costs tyres in the dirty air through the corners.

How the optimizer accounts for it

The lap-time formula gains an energy term, and the car gets a battery that is tracked lap by lap through the whole race. Every lap is driven in one of three modes:

Around every pit stop the energy is scheduled the way a team would do it: a harvesting lap before the in-lap so the battery is full, a push in-lap to pull off or defend against an undercut, a push out-lap on cold tyres, and a recovery lap after that. If the battery is not sufficient for a push lap the car takes the clipping penalty instead – larger at circuits with long straights. Push and harvesting laps also affect tyre degradation, so the tyre curve is no longer perfectly linear.

8. How to read the curve

• Vertical axis: seconds behind the best combination. Zero is the optimum.
• Horizontal axis: the lap you stop on (with two stops: the first stop, with the best second stop factored in).
• One line per compound order. If two lines sit close together the choice between them is effectively free – then traffic and rivals decide.
• Flat bottom = wide window, the timing is forgiving. Sharp bottom = timing is everything.
• ⚠ uncertain next to a compound means the practice session contained too few long runs on it to estimate α reliably. Such compounds are excluded from the optimization by default.