> ## Documentation Index
> Fetch the complete documentation index at: https://offthepace.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# What pace did the field actually run, lap by lap?

> The trimmed field-average lap time across a race, blending fuel burn, tyre degradation, and track rubbering into one reference baseline.

To say a driver was "fast" you need a yardstick: what did the field run on that lap? The field pace curve builds that yardstick. It plots the trimmed field-average lap time as it evolves over race distance, blending fuel-load drop, tyre degradation, and track rubbering-in into a single reference baseline the curve every other decomposition measures against.

## What it shows

The chart overlays a smoothed reference, the raw mean, and a caution flag:

* **Smoothed curve**: a LOWESS-smoothed field pace that suppresses outliers from safety cars, pit entries, and stint boundaries. This is the primary answer to "what did the field actually run this lap?"
* **Raw trimmed mean**: the 20th–80th percentile lap time across all eligible cars per lap. The ribbon between the two series shows where smoothing diverges from the raw data a wide ribbon means a noisy lap (few cars, spread strategy).
* **Low-sample laps**: laps with fewer than 4 eligible cars (pit windows, early laps) are flagged and should be read with caution.

<Note>
  The fuel-corrected rate of change of this curve feeds the `base_track_pace_s` input to the seven-term decomposition so this is not just a chart, it is an upstream model input.
</Note>

## How to use it

1. **Select a race** from the filter bar; the curve loads.
2. **Read the smoothed curve** as the field reference for that race.
3. **Watch the ribbon width** where the smoothed and raw series diverge, the lap is noisy and the average is less reliable.
4. **Discount flagged low-sample laps** pit windows and opening laps have too few cars to average well.

## Reading the signal correctly

The curve is a **trimmed central tendency**, not the leader's pace or the fastest lap it deliberately discards the top and bottom 20% to resist outliers. Its shape combines several physical effects (fuel, tyres, track), so a downward slope is fuel burn and rubbering, not the field simply getting faster.

<Warning>
  Early laps and pit windows are sparse and flagged for a reason the curve there leans on a handful of cars and can swing. Don't read fine structure in the flagged regions.
</Warning>

## Data source

The chart queries `int_field_pace_curve` via DuckDB-Wasm in the browser, for a single race.

| Column                  | Meaning                                                          |
| ----------------------- | ---------------------------------------------------------------- |
| `smoothed_field_pace_s` | LOWESS-smoothed field reference pace                             |
| `trimmed_mean_pace_s`   | 20th–80th percentile lap-time mean per lap                       |
| `eligible_car_count`    | Cars contributing to the lap; gates the low-sample flag at `< 4` |

This is a **single-race** view across **2018–2024** data.

For the full model definition, see the [`int_field_pace_curve` reference](/reference/models/int/int_field_pace_curve).