> ## 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.

# Comparing drivers across regulation eras

> A season leaderboard of era-adjusted driver ratings on one comparable scale, anchored by drivers who raced on both sides of the 2022 regulation change.

The era translator answers the bar-argument question: was a 2019 season better than a 2024 one? It puts every driver-season on a single comparable scale, correcting for the 2022 ground-effect regulation shift, and presents it as a leaderboard rather than a timeline so you can line up drivers from different eras within one ranked view. Negative means faster than the era-normalised field average.

## What it shows

Each row is one driver-season rating:

* **Era-adjusted rating**: a Bayesian-shrunk seasonal residual, offset by the era shift estimated from 20 bridge drivers who raced on both sides of the 2022 boundary. Negative = faster than the era-normalised field average.
* **95% CI**: propagates both within-season sampling uncertainty and the era-offset uncertainty. A wider interval means fewer qualifying seasons for the bridge anchor or fewer clean laps for the driver.
* **Bridge anchor (★)**: drivers with ≥8 clean-race seasons spanning pre- and post-2022, used to anchor the era shift. Their ratings are the most directly comparable across eras.

This is the same underlying data as the [era ratings timeline](/app/era-ratings-timeline), presented as a season leaderboard for direct within-season cross-era comparison.

<Note>
  A minimum of 5 races is required for a driver-season to appear, so part-season cameos are excluded.
</Note>

## How to use it

1. **Select a season** to rank that year, or compare ratings across seasons on the shared scale.
2. **Look for the ★** bridge-anchored ratings are the safest to compare across eras.
3. **Read the CI** before ranking two adjacent rows; overlapping intervals are a statistical tie.
4. **Export the data** to build your own cross-era comparisons.

## Reading the signal correctly

The rating is **era-normalised and relative** it answers "how far ahead of their own era's field was this driver?", not "what lap time would they set today?". The cross-era comparison rests entirely on the bridge-driver offset.

<Warning>
  Non-bridge seasons inherit the era offset without anchoring it themselves, so their absolute cross-era level is less certain than a bridge driver's. Weight ★ rows more heavily for cross-era claims. See the [decomposition limitations](/decomposition/limitations).
</Warning>

## Data source

The chart queries `int_era_normalized_driver_rating` via DuckDB-Wasm in the browser.

| Column                                    | Meaning                                               |
| ----------------------------------------- | ----------------------------------------------------- |
| `era_adjusted_rating_s`                   | Era-normalised seasonal rating, the leaderboard value |
| `rating_ci_lower_s` / `rating_ci_upper_s` | 95% credible interval                                 |
| `is_bridge_driver`                        | Whether the driver anchors the era offset (the ★)     |

The data window covers **2018–2024**.

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