> ## Documentation Index > Fetch the complete documentation index at: https://playbook.smedleygroup.com/llms.txt > Use this file to discover all available pages before exploring further. # Tyre Deg & Life > Pre-race and actual degradation and tyre life for soft, medium and hard, side by side in large compound-coloured tiles. ## Overview Tyre Deg & Life puts the plan beside the race for each of the three dry compounds: a **Pre Race** column with the degradation rate and tyre life the strategy engine was given, and an **Actual** column with what the field is delivering so far. Each value sits in a tile filled with its compound colour, sized to read from a distance. Use it when you want one glance at whether the tyres are wearing the way the plan assumed, without opening the deg tables behind it. > [!NOTE] > > This is a race-only widget: outside a race session it shows "Session is not a race." and computes nothing. *** ## What It Shows ![Tyre Deg & Life, pre-race plan beside actual (Singapore 2026, lap 42)](https://mintcdn.com/smedley_group/kebxybooreg84opf/images/watchparty/tyre-deg-life.png?fit=max\&auto=format\&n=kebxybooreg84opf\&q=85\&s=be6939599f53a53fa20b0a23786fb0ed) A title, two column headings, and three rows per column (Soft, Med, Hard). Every row is a wide tile beside a narrow one, both in the compound's colour. | Element | Meaning | | - | - | | Title "Tyre Deg & Life" | The widget's name, scaled with the tile height so it reads from a distance | | "Pre Race" column | The race data parameters for this weekend: the per-compound primary deg and primary life | | "Actual" column | What the race has shown so far, as of the playhead | | Wide tile | The compound name and degradation in seconds per lap to two decimal places, for example "Soft 0.12". Medium is labelled "Med" | | Narrow tile | The tyre life in laps, a whole number | | Tile colour | The compound colour for soft, medium or hard, with dark text on all three | | "-" | The value is unknown. It is never replaced by a default | Tile text scales with the size of the tile, taking the smaller of the height-driven and width-driven size so it never overflows a narrow tile. ### How the Actual column is worked out * **Actual deg** is exactly the Live Deg Prediction median for that compound: the middle degradation rate across the valid stints in the Tyre Deg Table. It is reused as it stands, not re-derived. * **Actual life** is the longest stint run so far on that compound, across all drivers, counted in laps. A stint still in progress counts the laps it has run so far, and a manual compound correction is respected. That longest stint is shown **only if it exceeds the pre-race life**; otherwise the pre-race life is shown. * With **no pre-race life**, the longest stint stands in for it. * With **neither**, the tile shows "-". *** ## Data Behind It This widget has no insight metric of its own and carries no `model_id` or `model_version`: it is a client-side derivation, `buildTyreDegLife` in `src/screens/tyreDegLifeSummary.ts`. Its registry entry names the `stint_deg` source (the `insight:stint_deg` snapshots), because the Actual deg median is taken over the Tyre Deg Table's stints. * **Pre Race deg and life**: the weekend's `race_data` parameter row, the same per-compound primary deg and primary life that [Deg Prediction](/software/internal/watchparty/widgets/deg-prediction) shows. Parameters are data, so nothing is invented when the row is missing. * **Actual deg**: `buildLiveDegPredictions` in `src/screens/liveDegSummary.ts`, the median [Live Deg Prediction](/software/internal/watchparty/widgets/live-deg-prediction) shows. The same stint rules apply: a stint needs a fit and must clear the minimum stint length, and negative gradients are dropped. * **Actual life**: the stint columns that [Tyre Strategy](/software/internal/watchparty/widgets/tyre-strategy) draws, as of the playhead. The longest stint is found by `longestStintByCompound` and the choice against the pre-race life is made by `actualLife`, both in the same file. *** ## States > **Session is not a race** > > Outside a race session the whole tile shows "Session is not a race." and nothing is derived. > **No pre-race data** > > If the weekend's `race_data` bundle was never loaded, every Pre Race tile shows "-" (for example "Soft -" in the wide tile and "-" in the narrow one). The Actual column still works from the race itself. > **No valid stints yet** > > With no valid stint of a compound in the Tyre Deg Table, that compound's Actual deg shows "Soft -", "Med -" or "Hard -". Actual life can still show a value from the longest stint run. > **Each value degrades on its own** > > A missing deg does not blank the life beside it, and one compound being unknown does not affect the others. > **Playhead moved** > > The Actual column is recomputed as of that lap, so scrubbing back shrinks the longest stint and changes the median with it. Pre Race never moves. > **Live vs replay** > > Identical: the widget reads the same rows and parameters whichever the source. *** ## FAQ > **Why does Actual life equal the Pre Race life?** > > No stint on that compound has yet run longer than the pre-race life, so the pre-race life stands. The Actual tile only moves once the race has shown a longer stint than the plan assumed. > **Why is Actual life a number when there is no Actual deg?** > > They come from different places. Life needs only a stint to have been run, while deg needs a valid, fitted stint that clears the minimum length. > **Why do the values differ from the Deg Prediction widgets?** > > This widget shows degradation to two decimal places, where the Deg Prediction and Live Deg Prediction widgets show three. The underlying figures are the same ones. > **Does an in-progress stint count towards life?** > > Yes, for the laps it has run so far, so Actual life can grow lap by lap while a long stint is still going. *** ## Next Steps > **[Live Deg Prediction](/software/internal/watchparty/widgets/live-deg-prediction)** > > The median behind the Actual deg tiles. > **[Deg Prediction](/software/internal/watchparty/widgets/deg-prediction)** > > The pre-race figures behind the Pre Race column. > **[Tyre Deg Table](/software/internal/watchparty/widgets/tyre-deg-table)** > > The valid stints the Actual deg median is taken over. > **[Tyre Strategy](/software/internal/watchparty/widgets/tyre-strategy)** > > The stints the longest-stint life is read from. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.