NHL Goalscorer Model

A daily 3-leg NHL player parlay. The model is a short, documented blend of recent and season rates, opponent shot volume and goalie save quality, turned into Poisson probabilities for anytime goals, anytime points, and shot totals. Prices are decimal. Times are Australia/Melbourne.

Model probabilities, not advice. Nothing here suggests a stake.

Run locally

npm install
npm run job -- --date 2026-11-12
npm run dev

The app is at http://127.0.0.1:4317. With DATABASE_URL unset, slates and cached downloads live in ./data.

Grade a finished NHL date (box scores, not a made-up price):

npm run job -- --grade 2026-11-10

--force rebuilds a slate even after a game has started. Without it, a live or final game keeps the price it was saved with. Games that have not started are priced again, and the odds lines in the job result are from that run.

npm run job with no date does what the morning cron does: build the next open NHL slate and grade the one before it.

Scripts

Command	What it does
npm run dev	Next.js dev server on port 4317
npm run job -- --date YYYY-MM-DD	Build that NHL slate
npm run job -- --grade YYYY-MM-DD	Build if needed, then grade from box scores
npm test	Unit tests (Poisson, blending, adjustments, parlay, grading)
npm run typecheck	tsc --noEmit
npm run lint	ESLint
npm run build	Production build
npm run migrate	Apply db/migrations/001_init.sql when DATABASE_URL is set

Environment

Copy .env.example to .env.local. No real secrets ship in the repo.

Variable	Required	Purpose
DATABASE_URL	No	Postgres (Neon works). Unset uses the JSON file in DATA_DIR.
CRON_SECRET	For /api/cron	Vercel sends Authorization: Bearer <CRON_SECRET>. The CLI does not use it.
ODDS_API_KEY	No	The Odds API. The provider stays off when this is empty. Read when the job runs.
ODDS_API_MARKETS	No	Default player_goal_scorer_anytime,player_points,player_shots_on_goal.
ODDS_API_REGIONS	No	Default us. NHL player props are on US books; au does not carry them.
ODDS_API_CACHE_HOURS	No	How long a priced Odds API response stays in http_cache. Default 6.
ODDS_PROVIDERS	No	Default sportsbet,pointsbet,oddsapi.
DATA_DIR	No	File store and download cache. Default ./data.

Data

• NHL API at https://api-web.nhle.com: schedule, rosters, game logs, live box scores. The open page polls /api/live every 60 seconds only while a game is on or about to start. That route is cacheable for 30 seconds. Nothing polls when the page is closed.
• MoneyPuck season CSVs (skaters, goalies, teams), cached for 18 hours.
• Odds, in order, each allowed to fail:
  • Sportsbet public sportsbook JSON, with a normal browser user-agent and no login.
  • PointsBet public API (api.au.pointsbet.com).
  • The Odds API, only with ODDS_API_KEY. One US region, three player markets, decimal odds. A priced response is cached for several hours. The events list is free; each game costs markets × regions (3 credits with the defaults).

A leg without a real price shows “no price” and is not eligible for the parlay. Edge is model probability minus 1 / decimal odds (vig left in).

Model and parlay

See the About page in the app for the weights. Short version: last 10 games, decay 0.85, 65% recent once 80 minutes are in, Poisson probabilities, opponent shots-allowed factor and goalie goals-versus-expected clamped. The parlay is the three positive-edge prices from three different games that maximise the product of model probabilities.

Cron and deploy

vercel.json schedules GET /api/cron at 0 20 * * * UTC. On the Hobby plan the job runs once sometime during that hour (20:00–20:59 UTC):

• During Australian daylight saving (AEDT, UTC+11, roughly October to April) that is 7:00–7:59am Melbourne.
• During standard time (AEST, UTC+10) it is 6:00–6:59am Melbourne.

The board is ready before 8:00am Melbourne. The job uses the Melbourne calendar date, already the new day by 6am. It builds the earliest NHL date that still has a game to play or in progress — the slate whose games start later that Melbourne day, including when an early game on it has already dropped the puck — and grades the date before it.

The route checks Authorization: Bearer $CRON_SECRET and returns 401 otherwise. Set CRON_SECRET in the Vercel project. The job is safe to run twice. Games that have not started are priced again. A live or final game keeps its saved price, and an unpriced leg stays “no price”. The odds block in the response is from this run. The Odds API line includes creditsUsed and requestsRemaining (x-requests-remaining) so a repeat inside the cache window shows 0 credits spent.

export const maxDuration = 60 is set on the cron route. The first run of a day downloads MoneyPuck and a few hundred game logs, so a cold start can use most of that minute. Later runs hit the cache. On Vercel’s free tier the cache is the database when DATABASE_URL is set (the file system does not persist between invocations).

Deploy:

1. Push the repo and import it in Vercel.
2. Add CRON_SECRET. Add DATABASE_URL from a Neon (or other Postgres) store if you want the board to survive restarts. Run npm run migrate once against that database, or execute db/migrations/001_init.sql.
3. Optionally add ODDS_API_KEY.
4. Confirm the cron in the project’s Cron Jobs tab. You can also call /api/cron yourself with the bearer token.

Local Postgres is optional. Without DATABASE_URL the app is fully usable from ./data.