> ## 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_end_regime > Why did this stint end? Part of the [Strategy](/transform/families/strategy) family. Why did this stint end? One row per stint. The stint-life survival target treats every uncensored stint as a completed tyre life, but 28.8% of them end under a safety car, VSC or red flag - the moment the pit wall was handed a free stop, not the moment the tyre ran out. This model names the cause so a consumer can separate the tyre-limit process from the interruption process instead of fitting their mixture. It also owns is\_censored\_stint, which fct\_stint\_features reads from here, so "the driver's last stint of the race" has one definition. Precedence is declared in the model header: censoring outranks regime, and within an uncensored stint red\_flag > safety\_car > vsc > green. ## Lineage ```mermaid theme={null} flowchart LR int_stint_geometry --> int_stint_end_regime stg_results --> int_stint_end_regime int_stint_end_regime --> fct_stint_features style int_stint_end_regime fill:#e40404,stroke:#e40404,color:#fff ``` ## Overview | Property | Value | | ----------------- | --------------------------------------------------------------------------------- | | Layer | `intermediate` | | Family | [Strategy](/transform/families/strategy) | | Contract enforced | No | | Upstream | [`int_stint_geometry`](./int_stint_geometry), [`stg_results`](../stg/stg_results) | **20 tests** [guard](/transform/ci/overview) this model - 19 generic, 1 singular. ## Columns | Column | Type | Nullable | Tests | Description | | ---------------------- | ---- | -------- | ------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `stint_id` | | Yes | [`not_null`](/transform/ci/structural), [`unique`](/transform/ci/structural) | PK from int\_stint\_geometry. One row per stint. | | `race_year` | | Yes | [`not_null`](/transform/ci/structural) | Season year. | | `race_id` | | Yes | [`not_null`](/transform/ci/structural) | Race identifier (numeric FastF1 event id cast to string). | | `driver_id` | | Yes | [`not_null`](/transform/ci/structural) | FastF1 three-letter driver code (e.g. VER, HAM). | | `stint_number` | | Yes | | Stint ordinal within the driver's race. NULL for the 325 stints in 2018 built from laps FastF1 never assigned to a stint; those carry stint\_end\_cause NULL and end\_cause\_confidence 'unassigned\_stint'. | | `end_lap_id` | | Yes | [`not_null`](/transform/ci/structural) | Foreign key to stg\_laps - the lap the stint ended on, chronologically. For an uncensored stint this is the in-lap. | | `end_lap_number` | | Yes | [`not_null`](/transform/ci/structural) | Race lap number of the stint's final lap. | | `end_lap_in_stint` | | Yes | [`not_null`](/transform/ci/structural) | Chronological ordinal of the stint's final lap within the stint (equals stint\_length\_actual). | | `is_censored_stint` | | Yes | [`not_null`](/transform/ci/structural), [`accepted_values`](/transform/ci/range-and-domain) | TRUE when this is the driver's last stint of the race, so it ended at the flag or at retirement rather than at a tyre change. Remaining stint life on these laps is a lower bound, not an observation. Consumed by the stint-life survival model (ml/src/features.py) to set the AFT upper bound to +inf, and by the blind-test scoreboard to report censored and uncensored stints apart. Never a model feature. | | `end_regime` | | Yes | [`not_null`](/transform/ci/structural), [`accepted_values`](/transform/ci/range-and-domain) | Track regime in force on the stint's final lap, for every stint including censored ones. Severity precedence red\_flag > safety\_car > vsc > green, because one TrackStatus string can carry several codes at once. Crossed with is\_censored\_stint this reproduces the measured end-regime decomposition. | | `is_multi_regime_end` | | Yes | [`not_null`](/transform/ci/structural) | TRUE when the final lap carried more than one of red/SC/VSC, so severity precedence had to choose which one names the ending. | | `ended_on_pit_lap` | | Yes | [`not_null`](/transform/ci/structural) | TRUE when the stint's final lap carries a pit marker. FALSE on an uncensored stint means the tyre change is known from the existence of a later stint but is not visible on the lap itself. | | `was_running_at_flag` | | Yes | [`not_null`](/transform/ci/structural) | TRUE when the driver's classified status says the car was still circulating at the chequered flag ('Finished', '+N Lap(s)', 'Lapped'). Disqualification is resolved on distance instead, because it is a post-race ruling rather than a reason a stint ended. Only meaningful on a censored stint. | | `stint_end_cause` | | Yes | [`not_null`](/transform/ci/structural), [`accepted_values`](/transform/ci/range-and-domain) | Six-class answer to "why did this stint end": green\_pit, sc\_pit, vsc\_pit, red for the four uncensored causes, race\_end and retirement for the two censored ones. NULL where stint\_number is NULL - the row is an artefact of unassigned laps, not a stint that ended. | | `end_cause_confidence` | | Yes | [`not_null`](/transform/ci/structural), [`accepted_values`](/transform/ci/range-and-domain) | How confidently the cause is known. 'observed' where every input was read; 'inferred' where severity precedence had to choose, where the pit marker is missing on an uncensored stint, or where disqualification hides whether the driver was running; 'unassigned\_stint' where the row is not a stint. |