> ## 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.

# dim_compounds_season

> One row per circuit × compound × season.

<Note>Part of the [Reference](/transform/families/reference) family.</Note>

One row per circuit × compound × season. Lifts the compound\_cliff\_params seed into a typed dimension: cliff parameters estimated from stint survival analysis (Kaplan-Meier, fitted on 2018–2024 data   see tasks/coefficients/README.md). Every row carries fit\_date and data\_window for governance. Re-fit when a new season is ingested via make coefficients-fit.

## Lineage

```mermaid theme={null}
flowchart LR
  dim_compounds_season --> fct_cliff_prediction_features
  dim_compounds_season --> int_compound_cliff_predicted
  dim_compounds_season --> int_constructor_deg_sensitivity
  dim_compounds_season --> int_lap_residual_decomposed_qualifying
  dim_compounds_season --> int_pit_strategy_cost_curve
  style dim_compounds_season fill:#e40404,stroke:#e40404,color:#fff
```

## Overview

| Property          | Value                                      |
| ----------------- | ------------------------------------------ |
| Layer             | `reference`                                |
| Family            | [Reference](/transform/families/reference) |
| Contract enforced | No                                         |

**4 tests** [guard](/transform/ci/overview) this model  -  4 generic, 0 singular.

## Columns

| Column                       | Type      | Nullable | Tests                                  | Description                                                                                |
| ---------------------------- | --------- | -------- | -------------------------------------- | ------------------------------------------------------------------------------------------ |
| `circuit_key`                | `varchar` | Yes      | [`not_null`](/transform/ci/structural) | Event slug (grand-prix key) matching race\_id in stg\_laps.                                |
| `compound_code`              | `varchar` | Yes      | [`not_null`](/transform/ci/structural) | Compound identifier the cliff parameters were fitted for (e.g. SOFT/MEDIUM/HARD or C1–C5). |
| `season`                     | `integer` | Yes      | [`not_null`](/transform/ci/structural) | Season year the parameters apply to.                                                       |
| `compound_grip_peak`         | `double`  | Yes      |                                        | Fitted peak grip level (relative pace offset at the compound's best window).               |
| `compound_wear_gradient`     | `double`  | Yes      |                                        | Fitted linear wear rate (pace loss per lap before the cliff).                              |
| `compound_optimal_temp_low`  | `double`  | Yes      |                                        | Lower bound of the compound's optimal operating-temperature window (°C).                   |
| `compound_optimal_temp_high` | `double`  | Yes      |                                        | Upper bound of the compound's optimal operating-temperature window (°C).                   |
| `compound_cliff_onset_laps`  | `double`  | Yes      |                                        | Fitted Kaplan-Meier cliff-onset age (laps) at which performance falls off sharply.         |
| `compound_cliff_severity`    | `double`  | Yes      |                                        | Fitted magnitude of the pace drop once the cliff is reached.                               |
| `fit_date`                   | `date`    | Yes      | [`not_null`](/transform/ci/structural) | Date on which the cliff parameters were last estimated.                                    |
| `data_window`                | `varchar` | Yes      |                                        | Season range the fit was estimated over (governance provenance).                           |
| `notes`                      | `varchar` | Yes      |                                        | Free-text provenance / caveat notes carried from the seed.                                 |