Buddy Cup

The idea

Every buddy golf trip has the same problem: someone becomes the human spreadsheet. Tee times live in a group text, matchups on a napkin, and nobody can actually score match play with handicaps — so the "cup" gets settled by vibes. Buddy Cup replaces all of it. From signed-up to first tee shot in an afternoon: create the trip, invite your buddies, snap your scorecards, schedule your cup, and plan the surrounding chaos — flights, shuttles, dinners, the post-round bar stop — all on one shared, day-by-day timeline next to the golf.

Inside a trip

Here's what a four-day cup looks like from the inside. Pick a day: the cup score updates through that day, every match shows its result or its live status, and every player's net score for the round sits beside it. Saturday is mid-round, so four singles matches are still live.

Signature features

• Real match-play scoring — not stroke-play with a coat of paint. The engine speaks the actual language of the Ryder Cup: DORMIE, AS, 3&2. Handicap strokes are allocated USGA-style against each hole's stroke index, net scores are compared per hole, and closeouts are detected the moment a match becomes mathematically over. Supports singles, 2v2 best ball, two-man aggregate, scramble, and house formats — with multiple handicap methods selectable per match
• AI scorecard reader — adding a course used to mean typing 54+ numbers. Now you photograph the scorecard and Claude's vision model extracts par, stroke index, and per-tee yardage/rating/slope for all 18 holes — with validation that falls back to manual entry rather than ever writing garbage data
• Arcade matchup portraits — players upload a photo and an AI image pipeline returns a 1994-NBA-Jam-digitizer version of them: pixelated, palette-crushed, transparent background, composited onto gold-framed matchup cards with team-color glows, CRT scanlines, and handicap-driven rating bars. Matchup reveals feel like a fight card
• The feed — a team chat built for the trip, not for productivity. Score posts, hole-tagged photos, emoji reactions, and trash talk — auto-moderated by an image-moderation service so admins don't have to babysit
• Live cup scoreboard — broadcast-graphics hierarchy: team total on top ("8½ – 6½, 6 points left"), per-match status cards and an individual leaderboard below, updating as holes post
• Lazy-claim roster — the admin seeds every player slot with email, nickname, and handicap; players claim their slot on first login via magic link. The trip is fully operational on day one even if half the group never signs in

More games than the cup

A buddy trip isn't only the cup. Every round can carry its own side action, scored by the same engine and kept separate from cup points:

• Formats: singles, 2v2 best ball, two-man aggregate, scramble, and stroke play, resolved by match play, Stableford, or stroke
• 30 Ball and 40 Ball: each side commits a budget of balls hole by hole, with a pace rule that keeps the budget reachable and scores net against par
• Bingo Bango Bongo, plus a game pack with Skins, Vegas, and Quota and a named Nassau preset
• Presses: match-play side bets tracked per match, never counted toward the cup

On the course: iPhone and Apple Watch

A native SwiftUI iPhone app shares the website's Clerk sign-in and covers the trip end to end: the cup, the schedule, the feed, score entry, and even building matches and new events. An Apple Watch companion lets you pick your group and enter hole scores from your wrist, without pulling out your phone mid-round.

Build strategy

• The scoring engine is a pure-function package: match-play math is the most algorithmically important code in the app, so it lives in its own workspace package with zero database or framework dependencies — inputs in, results out — covered by unit and property-based tests that make exotic formats safe to add
• Multi-tenant from day one: every domain table was trip-scoped while v1 served a single real 12-man trip. That insurance paid off: the trip-creation wizard, invites, and trip kinds (multi-day trips, one-day outings, single matches) shipped as routing and forms, not a rewrite
• Permissions in the application layer: all authorization cascades through one set of helpers — platform admin → trip admin → captain → self — so a permission rule is one function, not a policy scattered across tables
• AI with a safety net: the scorecard reader validates its output and falls back to manual entry, and portrait generation never destroys the source photo. AI accelerates the happy path; it never gatekeeps it
• Polling-first realtime: golf doesn't need millisecond updates. TanStack Query polling keeps the leaderboard live with a fraction of the infrastructure of WebSockets — architecture matched to the actual problem
• Built against a real trip: the whole product is pressure-tested by an actual 12-man, 6-round cup — real handicaps, real tee times, real trash talk. Nothing ships that wouldn't survive contact with 12 opinionated golfers