RallyUp

RallyUp was inspired by our badminton club experience, where it was hard to find fair matches. Using ELO ratings, RallyUp helps players discover their skill level and grow through fair matches.

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RallyUp

Badminton event finder with ELO-based ranking system.

Inspiration

Three months ago, we founded SU Badminton Club with 48 members. Hosting open play sessions revealed two problems: players struggled to find matches quickly, and skill-matched opponents were hard to locate. Casual players, competitive improvers, and club teams need tools to connect and track progress. We built RallyUp to solve this.

What It Does

RallyUp helps badminton players find events and track their competitive ranking. Core Features:

  • Event Discovery - Browse and join practice sessions or competitive matches filtered by location, type, and skill rating
  • Smart Matchmaking - Rating-range filters ensure players compete against similar skill levels
  • ELO Ranking System - Track rating changes after each match with transparent score calculations
  • Match Management - Hosts create events, submit scores, and the system auto-assigns balanced teams for doubles
  • Match History - Review past competitions, scores, and rating progression ## How We Built It | Layer | Technology | |-------|------------| | Frontend | Flutter (Dart) - cross-platform iOS/Android | | State Management | Provider pattern for reactive UI updates | | Backend | Firebase (Authentication, Cloud Firestore) | | Auth | Microsoft SSO for university integration | ## Challenges We Ran Into

We wanted RallyUp to cover all the core functionalities and make sure they were ready to demo. The challenge we ran into was how to quickly split the tasks between three team members, and be ready to beta test the new functionalities during production and try to make it as simple as possible so that we can present it after the hackathon.

Accomplishments We're Proud Of

So, we managed to build a cross-platform app in a hackathon timeframe. Can't wait to try it out during the Badminton open play THIS AFTERNOON! (Especially the ELO rating system that calculates expected scores and applies rating deltas)

What We Learned

First, teamwork and well-managed version control! Second, talking to mentors for thoughts is a good design practice for confirming the development plan and scope. Finally, one tech tips, using Firebase Firestore data modeling for nested relationships (events → matches → players)

What's Next for RallyUp

  • Club Rollout - Deploy to SU Badminton Club members and gather feedback
  • Android & Web - Expand beyond iOS to reach more players
  • Bluetooth Quick Match - Let nearby players form instant 1v1 or 2v2 matches
  • Chat Integration - Add messaging for event coordination
  • Leaderboards - Display club and regional rankings
  • Generalization - We want to add more sports into the app and make it usable for all kind of sports
  • Robustness - We want to add more validations and cover more cases so that our apps can be more robust

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