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Overview

Tyre Strategy shows the whole field’s stint sequence on one lap-number axis: every driver’s row is their stints laid out as compound-coloured blocks, so you can read undercut and overcut patterns, compound splits, and stop timing across the field at a glance. Reach for it whenever you need the race’s strategic shape rather than one driver’s detail.
This is a race-only widget: outside a race session it shows “Session is not a race.” and computes nothing.

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What It Shows

Tyre Strategy mid-race: hatched used sets and unfinished open stints (Madrid 2026, lap 43) One row per driver, each stint drawn as a block on a lap axis that spans the whole race, lap 1 at the left. Two orderings, your choice. A toggle switches the rows between car number, a stable reference grid that never re-sorts, and running order, which takes the timing tower’s own as-of order so the rows read top to bottom as the race currently stands. Hovering a segment is the only way to see its detail. Right-click a segment to open the compound picker and correct that stint’s tyre by hand: the same menu the timing tower’s badge and the Stints viewer open, offered here because the whole stint is already on screen.

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Data Behind It

This widget has no dedicated insight and carries no model_id/model_version: it is a pure client-side derivation over the same stint rows the Stints widget reads, built by buildTyreStrategyColumns in src/screens/derive.ts.
  • Rows: GET /v1/sessions/{session_key}/stints, hydrated on session enter and re-hydrated on seek or reconnect. Stint rows carry no channel of their own on the wire; live updates arrive wrapped as timing-channel envelopes and route to the stint reducer by the presence of a stint_number field.
  • Row membership and order: the builder returns rows in fixed car-number order; the running-order option re-orders them using the timing tower’s own entries, which is the one place in the app allowed to decide a running order.
  • Compound: the stint row’s own compound, with a manual override for that stint winning and marked as edited.
  • Flag bands: buildStintFlags (safety car, virtual safety car, red flag periods, plus track-level sector-yellow spans) mapped onto the lap axis via buildStintAxisLaps’s per-lap timing ticks - the identical overlay data the Stints widget’s own flag bands use.
  • Axis span: transport.totalLaps fixes the axis to the full race; if that is not yet known, the axis falls back to the furthest lap any segment currently reaches.

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States

Shows “No stints yet.” whenever no driver has a usable stint segment, or the axis span cannot be determined - typically the first laps of a race before any stint row has arrived.
Wire-identical: the widget reads the same stint rows and channel envelopes regardless of source, and never branches on it.
Race-only. Outside a race, the widget shows “Session is not a race.” - the app never computes the tyre-strategy data bundle for a non-race session.
An unreported compound renders a neutral grey block rather than a guessed colour. An unreported starting tyre age (tyre_age_at_start) is never assumed to be a fresh set: the tooltip’s tyre-life reads ”?” instead of “new”.
If flag data or lap-time ticks are not yet available, the overlay simply does not draw - not an error state, just nothing to show yet.
A driver’s latest stint grows lap by lap with the playhead and shrinks correctly on scrub-back. It is truncated so it never overlaps a successor stint that has already reported in, which can otherwise happen during a brief live coalescing window.

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FAQ

A hatch marks a used set on the same base compound colour, so the compound stays legible at a glance regardless of wear. A paler “used” shade was tried and dropped because it made the compound itself harder to read.
The stint row did not report a starting tyre age. Rather than assume the set was fresh, the widget renders the honest “unknown” state.

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Next Steps

Stints

The same stint data at per-lap detail, on a time-of-day axis.

Tyre Deg Table

Per-stint degradation fits for every driver.

Tyre Deg Ranking

Compound-by-compound degradation ranking across the field.

Race Control

The flag periods this widget’s overlay bands are drawn from.
Last modified on September 18, 2026