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The era ratings timeline draws every driver’s career as a line of era-adjusted pace, expressed in seconds relative to the field after normalising for the 2022 ground-effect regulation change. A 2018 rating sits on the same scale as a 2024 rating, so you can read a career arc rise, peak, decline without a regulation reset hiding inside it. Negative means faster than the era-normalised field average.

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What it shows

Each line is one driver’s season-by-season rating:
  • Era-adjusted rating: the per-season skill residual after the regulation offset is applied. Negative = faster than the era-normalised field average.
  • Bayesian shrinkage: per-season residuals are shrunk toward the season league average. Drivers with fewer races have wider intervals and estimates pulled closer to zero the uncertainty is honest, not hidden.
  • Era calibration: the 2022 offset is estimated from 20 “bridge drivers” with ≥8 clean-race seasons on both sides of the boundary, then applied to all pre-2022 seasons. Bridge drivers render as solid lines; non-bridge drivers as dashed.
  • 95% CI ribbon: propagates both the per-season shrinkage standard error and, for pre-2022 seasons, the era-offset estimation uncertainty.
Dashed (non-bridge) lines before 2022 lean more on the estimated era offset than on the driver’s own cross-era racing, so their absolute level is less certain than a solid line’s.

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How to use it

  1. Select drivers to add or remove their career lines.
  2. Read line style solid lines are anchored by cross-era racing; dashed lines inherit more offset uncertainty.
  3. Compare ribbon overlap between two drivers in the same season: overlapping ribbons mean the gap is within noise.
  4. Follow a single arc across seasons to see development, peak, and decline on one continuous scale.

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Reading the signal correctly

The rating is a relative measure it places a driver against the era-normalised field, not on an absolute lap-time scale. A flat line across a regulation boundary is the goal of the era correction, not evidence the driver stood still.
Pre-2022 absolute levels depend on the bridge-driver offset. If you care about cross-era comparisons specifically, weight the solid (bridge) lines more heavily and treat dashed early-season levels as wider than the ribbon alone suggests. See the decomposition limitations.

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Data source

The chart queries int_era_normalized_driver_rating (built on int_driver_season_ratings) via DuckDB-Wasm in the browser; the clean-lap filter is applied upstream. The data window covers 2018–2024. For the full model definitions, see the int_era_normalized_driver_rating reference and the int_driver_season_ratings reference.