fct_stint_features

One row per stint.

Part of the Marts family.

One row per stint. Pit strategy feature table: compound, stint length, tyre age progression, thermal load buildup, cumulative dirty air tax, cliff onset lap, and pace degradation slope. Used to model pit strategy decision: is it time to box? Includes tyre_management_score and pit_decision_class derived from int_pit_strategy_value.

Lineage

Overview

Property	Value
Layer	marts
Family	Marts
Contract enforced	No
Tags	feature_engineering, simulation
Upstream	int_stint_geometry, int_stint_end_regime, stg_laps, int_lap_thermal_proxy, int_dirty_air_tax_component, int_lap_anomaly_flags, int_lap_residual_decomposed, int_pit_strategy_value

17 tests guard this model - 16 generic, 1 singular.

Columns

Column	Type	Nullable	Tests	Description
stint_id		Yes	not_null, unique	PK from int_stint_geometry
driver_id		Yes	not_null	FastF1 three-letter driver code (e.g. VER, HAM).
race_id		Yes	not_null	Race identifier (numeric FastF1 event id cast to string).
race_year		Yes	not_null	Season year.
stint_length_laps		Yes	not_null, expect_column_values_to_be_between	Total laps in this stint
compound		Yes		Tyre compound for this stint
starting_tyre_age_laps		Yes		Tyre age at the start of this stint (before first lap)
cumulative_thermal_load_end		Yes		EW cumulative thermal load at the end of the stint
cumulative_dirty_air_tax_s		Yes		Sum of dirty air tax across all laps in the stint
cliff_lap_in_stint		Yes		Lap position within stint where cliff is first detected (NULL if no cliff)
tyre_management_score		Yes	expect_column_values_to_be_between	Tyre management score: actual end-of-stint driver residual normalised against the optimal pit opportunity cost. Low score = good management. Clamped to [-3, 3] - it is a ratio, and its denominator can be arbitrarily small, so it is unbounded in whichever direction that happens from. Only the ceiling existed until 2026-08-23.
end_of_stint_pace_falloff_s_per_lap		Yes		OLS slope of driver_skill_residual_s over last 3 laps. NULL when short_stint_flag = TRUE.
short_stint_flag		Yes	not_null	TRUE when stint_length_laps < 3 (slope is NULL/unreliable)
pit_decision_class		Yes		Pit strategy decision verdict from int_pit_strategy_value (optimal / overran / undercut_forced / early).
is_censored_stint		Yes	not_null, accepted_values	Passed through from int_stint_end_regime, which owns the definition. 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, accepted_values	Passed through from int_stint_end_regime. Track regime in force on the stint’s final lap (green / safety_car / vsc / red_flag), severity precedence red_flag > safety_car > vsc. Recorded for censored stints too, where it is a fact about the lap rather than the reason the stint ended - read stint_end_cause for that.
stint_end_cause		Yes	accepted_values	Passed through from int_stint_end_regime. Why the stint ended: green_pit, sc_pit, vsc_pit, red (the four uncensored causes) or race_end, retirement (the two censored ones). 28.8% of uncensored stints are sc_pit / vsc_pit / red, i.e. the pit wall taking a free stop rather than the tyre reaching its limit, so anything fitting or scoring stint life reads this alongside is_censored_stint. NULL on the 325 2018 stints built from laps FastF1 never assigned a stint number. Never a model feature.
end_cause_confidence		Yes	not_null, accepted_values	Passed through from int_stint_end_regime. ‘observed’, ‘inferred’ (severity precedence had to choose, the pit marker is missing, or disqualification hides whether the driver was running) or ‘unassigned_stint’ (the row is not a stint).