You can usually spot the moment the real tyre call gets made.

It’s not on the grid, with the cameras and the blankets and the dramatic close-ups.

It’s on a laptop, 90 minutes earlier, when someone quietly says: “If we start Medium, we’re racing cars. If we start Soft, we’re racing the window.”

Because starting tyre choice in Formula 1 isn’t “soft vs medium.” It’s a decision tree built around gaps: the gap between your qualifying position and your true race pace, the gap between theoretical pit windows and usable ones, and the gap between what your model predicts and what Turn 1 traffic will allow.

In 2025, those gaps mattered more than ever. Lando Norris won the Drivers’ Championship with 423 points, just 2 ahead of Max Verstappen on 421 — and McLaren took the Constructors’ title with 833.

And crucially: there is no fastest-lap bonus point from 2025 onwards, so strategy isn’t padded by a “free” extra point at the end. Every decision has to pay back in positions, not hero laps.

Below is the real decision tree teams use when choosing starting tyres — with the data inputs that actually move the needle.

The constraints teams can’t negotiate (even with perfect data)

Before the decision tree starts, teams lock in the rules and the weekend context.

1) Race tyre rules: you’re not picking one tyre — you’re picking the order

In a dry race, drivers must use at least two different slick compounds. That means your “starting tyre” is really your first lever in building:

  • a one-stop structure (long first stint, defend the undercut)
  • a two-stop structure (short first stint, weaponize pace)
  • a reactive structure (keep options open for Safety Car timing)

2) Tyre inventory: the best tyre is the one you still have

Your starting set isn’t always the best compound — it’s the best available compound.

Weekends with extra sessions (and especially Sprint formats) change the math because they change what’s left as a new vs scrubbed set. In 2025, Sprints ran at Shanghai, Miami, Spa, Austin, São Paulo, and Qatar — which often pushed teams into riskier “used tyre” compromises on Sunday.

The decision tree (what teams actually evaluate, in order)

Step 1: What is the race’s “tyre story” — thermal or degradation?

Teams begin with a stint model built from:

  • long-run pace (usually FP2/FP3), corrected for fuel
  • degradation curves (lap time drop-off per lap)
  • thermal behaviour (surface overheating vs stable temps)

If the race is degradation-limited, starting Medium/Hard gains value because it keeps the first stint alive long enough to reach the “clean” one-stop window.

If the race is traction/temperature-limited, starting Soft can be worth it because the first 5–10 laps are where the tyre actually switches on.

Data-driven reality: the “fast” tyre often isn’t the fastest over 20 laps — it’s the tyre that stays within ~0.2–0.4s of peak without forcing you into early traffic.

Step 2: How much is track evolution worth — and when?

Track evolution doesn’t just affect qualifying. It changes how painful (or powerful) an early stop becomes.

  • High evolution tracks reward later stints on a better surface — making early-stopping less attractive unless you can guarantee clear air.
  • Low evolution tracks make undercuts more potent because new tyres immediately outperform old tyres.

This is why the same compound choice can flip between circuits on the same calendar:

  • Melbourne, Suzuka, Silverstone: evolving grip and high-speed load make stint timing sensitive.
  • Monaco: low tyre stress, track position, and traffic define almost everything.

Step 3: What is the pit lane time loss — and can you pass to earn it back?

The pit stop delta (pit lane time loss) sets the price of flexibility.

If overtaking is difficult, a stop is expensive because you can’t easily recover track position. That shifts value toward:

  • longer first stints (often Medium)
  • protecting against being undercut
  • prioritising clean air over raw tyre pace

If overtaking is easier, teams can “spend” stops more freely — making a short Soft first stint into an aggressive two-stop a realistic weapon.

Step 4: Where are you starting, and what traffic profile does that create?

Grid position is the first branch in the tree.

### If you’re starting P1–P3: control beats pace

At the front, the goal is usually to avoid giving rivals a clean undercut.

Typical logic:

  • Start Medium if degradation is meaningful: defend the window and keep the one-stop alive.
  • Start Soft if you need launch/traction to survive Turn 1 or defend a vulnerable pole.

### If you’re starting P4–P10: you’re choosing a fight

In the points positions, you’re often boxed into traffic. Starting tyre choice becomes a bet on whether you can:

  • clear slower cars early (Soft helps)
  • extend and jump traffic with a later stop (Medium helps)

A common split is:

  • Soft if you believe you can gain 1–3 places in the first stint and convert it into clean air.
  • Medium if you expect a DRS train and want to extend until the field spreads.

### If you’re starting P11–P20: your starting tyre is a weapon, not a preference

Outside the top 10, the decision is less about defending and more about creating an offset:

  • Start Hard/Medium to run long and pick up positions when others pit.
  • Start Soft only if you can realistically clear into free air quickly (rare).

Step 5: Undercut vulnerability (and why “covering” isn’t always possible)

Teams model the undercut with a simple question:

If the car behind pits now, do we lose position before our tyres recover?

The answer depends on:

  • tyre warm-up (new tyre performance in lap 1–2)
  • out-lap traffic
  • whether the track punishes cold tyres

Some cars are warm-up monsters; some need multiple laps to come alive. In 2025, the best teams didn’t just choose compounds — they chose compounds that matched their car’s warm-up profile.

If you want the broader picture of how this played out across the year, pair this with our undercut/overcut deep dive: Undercut vs Overcut in 2025: What Actually Worked.

Step 6: Rival modelling (the part fans underestimate)

Starting tyres are often chosen against a person, not against a track.

Teams run “rival trees”:

  • If Verstappen starts Soft behind us, can he force an early stop?
  • If Norris starts Medium, can we pressure him into a defensive pit?
  • If our teammate is behind, do we split to cover both?

That last point matters: split strategies are a championship tool, not a vibe.

McLaren’s 2025 title wasn’t built only on peak pace — it was built on controlling races with two cars near the front, repeatedly forcing rivals to choose between covering one threat and exposing themselves to the other.

Step 7: Safety Car probability (and why it changes the “best” tyre)

A Safety Car doesn’t just compress gaps — it changes which stints are valuable.

  • If SC probability is high, starting Medium can be strong because it keeps you flexible for a cheap stop.
  • If SC probability is low, a Soft start may be worth more because you’re maximizing early pace in a “pure” race.

This is where teams make very different calls at, say, Baku vs Barcelona — even if the compounds on paper look similar.

A simple “if/then” cheat sheet (RaceMate edition)

Here’s the decision tree compressed into actionable logic:

  • If overtaking is hard + degradation is moderate/high → start Medium (protect track position, control the window).
  • If you’re vulnerable at the start (dirty side, launch risk) → start Soft (survive Turn 1, then manage).
  • If you expect a DRS train in stint 1 → start Medium (extend until the train breaks).
  • If you need to create clean air quickly → start Soft (attack, then pit into space).
  • If you’re outside the points and need an offset → start Hard/Medium (build a different race).

And remember: with no fastest-lap bonus point in 2025+, the “late stop for an extra point” incentive is gone. Endgame strategy is cleaner — which makes the start proportionally more important.

A 2025 championship lens: why starting tyres became a title lever

When a season finishes Norris 423 to Verstappen 421, every position swing matters.

That’s why starting tyre calls increasingly looked like this:

  • Championship leader: prioritize risk control (avoid getting undercut, avoid first-lap chaos, bank points).
  • Chaser: prioritize volatility (force earlier decisions, create alternative windows, gamble on pace offsets).

In a 24-round calendar spanning everything from Melbourne to Abu Dhabi, the “right” start compound changes weekly — because the tree changes weekly.

If you want to see how even small changes in finishing positions swing the title in a no-fastest-lap-point world, run your own scenarios in our championship calculator: RaceMate Points Simulator.

What to watch next race: the three tells that reveal the real starting-tyre plan

  1. Q2 run plan: teams that are truly leaning Soft will often preserve a cleaner Medium set (or vice versa) depending on expected stint length.

  2. Teammate divergence: if a team splits compounds in the top 10, it’s usually because they’re more worried about covering rivals than maximizing a single “best” strategy.

  3. Radio language: when you hear “protect the window” vs “push to make the offset,” you’re hearing the decision tree in real time.

Conclusion: the starting tyre isn’t a choice — it’s a commitment to a kind of race

The grid makes it look binary: Soft or Medium.

But teams aren’t choosing a rubber compound. They’re choosing:

  • whether to fight early or build later
  • whether to defend a window or attack one
  • whether to bet on clear air, or bet on traffic surviving

In 2025, with a title decided by two points and the fastest-lap bonus removed, the margin for “pretty good” decisions disappeared.

Starting tyres are where strategy becomes identity.

And the teams that win aren’t the ones who pick the fastest tyre.

They’re the ones who pick the tyre that closes the right gap — before the race opens a dozen more.

*Further reading: The 10 Best Strategy Calls of 2025 • The 10 Worst Strategy Calls of 2025 • Quali Pace vs Race Pace: Which Teams Were “Fake Fast”?