- A lap is split into three sectors by two timing lines between the start and the finish. Each is timed on its own.
- Purple = the fastest time anyone has set in that sector this session.
- Green = a driver's own best in that sector, but not the fastest overall.
- Yellow = slower than that driver's own best.
- A driver's three best sectors added together are their theoretical best lap.
Three sectors, two timing lines
A lap is timed from the start-finish line back to it. Two more timing lines split it into three sectors, and each sector is timed separately — so instead of one number per lap, you get three, and you can see which part of the lap was quick.
Sectors are not equal thirds. The lines sit wherever suits the circuit, so one sector may be two long straights and a chicane while another is a run of slow corners. A sector time only means something against other times in the same sector, at the same circuit.
F1 25 reports sector 1 and sector 2 times with every lap, to the millisecond; sector 3 is the rest of the lap time. In the worked example used across these guides — a circuit the length of Monza — the sector lines fall at 1,900 m and 3,850 m of a 5,793 m lap.
Purple, green and yellow
| Colour | Means | In plain words |
|---|---|---|
| Purple | The fastest time set by anyone in that sector (or for the lap) in the session so far | Leading. It can be taken away by the next driver through. |
| Green | The driver's own best in that sector this session, but not the overall best | Improving on themselves, but someone else has been quicker. |
| Yellow | Slower than the driver's own best so far | No improvement — which is not the same as slow. |
The same convention colours whole lap times, and F1 25's own timing displays follow it too. Everything is judged at the moment the time is set, against everything set before it — which is why the colours on a timing screen keep changing as a session goes on.
An evening on the timing screen
Here is the example session as a live timing screen would have coloured it, if another driver had already set the target lap — 1:20.243, quicker than you in every sector — before you went out. Only counted laps are shown: the out-lap and the lap invalidated for track limits set nothing.
| Driver | Lap | S1 | S2 | S3 | Lap time |
|---|---|---|---|---|---|
| Other driver | target | 28.197 (purple) | 27.980 (purple) | 24.066 (purple) | 1:20.243 (purple) |
| You | lap 2 | 28.852 (green) | 28.344 (green) | 24.362 (green) | 1:21.558 (green) |
| You | lap 3 | 28.599 (green) | 28.279 (green) | 24.332 (green) | 1:21.210 (green) |
| You | lap 5 | 28.383 (green) | 28.243 (green) | 24.334 (yellow) | 1:20.960 (green) |
| You | lap 6 | 28.714 (yellow) | 28.172 (green) | 24.274 (green) | 1:21.160 (yellow) |
| You | lap 7 | 28.786 (yellow) | 28.296 (yellow) | 24.112 (green) | 1:21.194 (yellow) |
| You | lap 8 | 28.530 (yellow) | 28.190 (yellow) | 24.230 (yellow) | 1:20.950 (green) |
Three things stand out. First, you never go purple: the other driver's sectors are quicker than any of yours, so your best is green at most. Second, green sectors keep appearing through the evening as you improve on yourself. And third — the one worth remembering — your best lap of the night, lap 8 at 1:20.950, has three yellow sectors. It set no personal best in any sector; it was simply the lap with no bad one.
Why a purple sector does not always mean a fast lap
- The lap may not finish. A driver can go purple in the first sector and then lose it all — traffic, a mistake, a lock-up — in the next.
- The track gets quicker. As a session goes on, rubber goes down and the surface grips better, so late purples are common and early ones fragile.
- Conditions change. Fuel, tyres, a tow down a straight, wind: a purple sector is the fastest time in the session, not the best driving.
- Laps get deleted. A lap that breaks track limits is struck off, sectors and all. In the example, the quickest lap of the evening was invalidated and set nothing.
Mini-sectors: the same idea, finer
Three sectors say which third of the lap was quick. Live timing often goes further, splitting each sector into smaller mini-sectors coloured the same way, so you can watch a lap go purple or yellow almost corner by corner.
StintLab does the same with your own laps, at an even finer cut: it divides the lap into 100 m pieces and takes the quickest you drove through each, all session. Added up, that is your optimal lap — and up to five of the pieces where your best lap fell short by 0.050 s or more are listed, worst first.
Best sectors add up: the theoretical best
Take a driver's best time in each sector — from whichever laps they came from — and add them together. That is the theoretical best, sometimes shown on broadcasts as an “ideal lap” to make the point that the pole time was there, in pieces. In the example:
StintLab marks your best of each sector with ◆ in the lap table, so the theoretical best is visible at a glance:
| Lap | Time | Gap | S1 | S2 | S3 | Counts |
|---|---|---|---|---|---|---|
| 1 | 1:35.518 | — | 42.581 | 28.471 | 24.466 | out-lap |
| 2 | 1:21.558 | +0.608 | 28.852 | 28.344 | 24.362 | counted |
| 3 | 1:21.210 | +0.260 | 28.599 | 28.279 | 24.332 | counted |
| 4 | 1:20.623 | — | 28.337 | 28.101 | 24.185 | invalid |
| 5 | 1:20.960 | +0.010 | ◆ 28.383 | 28.243 | 24.334 | counted |
| 6 | 1:21.160 | +0.210 | 28.714 | ◆ 28.172 | 24.274 | counted |
| 7 | 1:21.194 | +0.244 | 28.786 | 28.296 | ◆ 24.112 | counted |
| ◆ 8 | 1:20.950 | — | 28.530 | 28.190 | 24.230 | counted |
How it is kept honest — only counted laps, sectors that must add up to the lap time — is in theoretical best, optimal lap and time available.
Questions
What does a purple sector mean in F1?
The fastest time anyone has set in that sector during the session so far. It can be lost a minute later if another driver goes quicker, which is why purple sectors appear and disappear through a qualifying session.
What does a green sector mean?
A driver's own best time in that sector this session, which is not the fastest of the session overall. Green means improving; purple means leading.
What does a yellow sector mean?
A sector slower than that driver's own best so far in the session. It is not necessarily slow — a driver's best lap can be made of yellow sectors, because the best lap is the one without a bad sector rather than the one with three record sectors.
Are the three sectors the same length?
No. Sector boundaries are set per circuit, at timing lines placed where the layout suits, so one sector can be much longer or more twisty than another. A sector time only means something against other times in the same sector.
What are mini-sectors?
Smaller timed splits inside each sector, used by live timing to show in finer detail where a lap is gaining or losing. Coloured the same way, they show a lap turning purple or yellow corner by corner rather than third by third.
Where do F1 25 sector times come from in StintLab?
The game reports sector 1 and sector 2 times with its lap data, to the millisecond; sector 3 is the lap time minus the other two. StintLab keeps all three with every lap, marks your best of each sector in the session, and adds them up into your theoretical best.