# Sports Travel-Fatigue Estimator

> Travel distance, time-zone jumps, rest and back-to-backs per game as a fatigue score. Enter a team's schedule (date, city or coordinates). For every game the estimator computes the great-circle travel distance from the previous venue, the time-zone shift and its direction, rest days, back-to-backs and schedule density, and combines them into a 0–100 fatigue score with openly documented weights. It is a heuristic for comparing schedules, not a physiological measurement.

Part of usefulweb.site (https://usefulweb.site/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://sportstravelfatigueestimator.usefulweb.site/ (interactive tool at https://sportstravelfatigueestimator.usefulweb.site/tool)
- JSON API: POST https://sportstravelfatigueestimator.usefulweb.site/api/v1/calculate with a JSON object of inputs (schema: https://sportstravelfatigueestimator.usefulweb.site/api/v1/tool)
- OpenAPI: https://sportstravelfatigueestimator.usefulweb.site/openapi.json
- MCP (Streamable HTTP): https://sportstravelfatigueestimator.usefulweb.site/mcp - tool `sports_travel_fatigue_estimator`

## Inputs
- homeBase (text, required): Starting city - A city from the bundled list (118 major sports cities) or coordinates like 42.36,-71.06.
- homeTimeZone (text): Starting time zone - Only needed for coordinates: an IANA zone like America/New_York or an offset like -5.
- games (table, required): Games - In date order. Location: a listed city or latitude,longitude. Time zone is only needed for coordinates.

## Method
- Travel distance: great-circle (haversine) distance between the previous venue (or the starting city) and this venue, with a mean Earth radius of 6371 km. Real road or flight routes are longer.
- Time-zone shift = UTC offset at the venue − UTC offset at the previous venue, on the game date (daylight saving time included via the IANA time-zone database). Positive = eastward (clocks ahead).
- Fatigue score (0–100, heuristic): travel 1 point per 100 km (max 30); time zones: hours of shift not yet recovered × 5 (eastward) or × 3.5 (westward), max 25, assuming recovery of 1 h per full day between games eastward and 1.5 h westward; rest: same-day game 30, back-to-back (next day) 20, one rest day 8, two rest days 3; density: 5 points for each game beyond 3 in the 7 days ending on the game day (max 15).
- Eastward travel is weighted more because research on Major League Baseball (Song, Severini & Allada, PNAS 2017) found jet-lag effects mainly after eastward travel. The exact weights are editorial choices to make schedules comparable, not fitted to data.
- Bands: below 25 low, 25–49 moderate, 50–74 high, 75 and above very high.

## Limits
- A transparent heuristic for comparing schedules. It does not measure an athlete's actual fatigue, sleep or readiness.