> ## 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.

# int_stint_power_law_fit

> WI-17: y = intercept + alpha * age^beta per stint, beta profiled on 0.20-3.00 (step 0.05) with REGR_SLOPE / REGR_INTERCEPT / REGR_R2.

<Note>Part of the [Physics](/transform/families/physics) family.</Note>

WI-17: y = intercept + alpha \* age^beta per stint, beta profiled on 0.20-3.00 (step 0.05) with REGR\_SLOPE / REGR\_INTERCEPT / REGR\_R2. One row per stint that can be fitted (two or more distinct ages, some spread in y); fit\_eligible marks the spec's stints (>= 8 laps, age span >= 7). Descriptive only: Step 0 found beta on the grid edge in \~65% of eligible stints and alpha's reliability ceiling \~0, so the per-stint R^2 distribution is reported, never gated. T50 pins the bounds.

## Lineage

```mermaid theme={null}
flowchart LR
  int_power_law_lap --> int_stint_power_law_fit
  style int_stint_power_law_fit fill:#e40404,stroke:#e40404,color:#fff
```

## Overview

| Property | Value |
| - | - |
| Layer | `intermediate` |
| Family | [Physics](/transform/families/physics) |
| Contract enforced | No |
| Upstream | [`int_power_law_lap`](./int_power_law_lap) |

**7 tests** [guard](/transform/ci/overview) this model  -  5 generic, 2 singular.

## Columns

| Column | Type | Nullable | Tests | Description |
| - | - | - | - | - |
| `stint_id` | | Yes | [`not_null`](/transform/ci/structural), [`unique`](/transform/ci/structural) | |
| `beta` | | Yes | [`not_null`](/transform/ci/structural) | |
| `r2` | | Yes | [`not_null`](/transform/ci/structural) | R^2 at the chosen beta. |
| `r2_linear` | | Yes | | R^2 of the straight line (beta = 1, on the grid). r2 >= r2\_linear always (T50). |
| `beta_at_grid_edge` | | Yes | | TRUE when beta landed on 0.2 or 3.0. |
| `fit_eligible` | | Yes | [`not_null`](/transform/ci/structural) | |


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.