Tennis Analyzer

Tennis Analyzer is a micro-level tennis performance analysis mobile app. Use this app to track point-by-point match data and generate detailed statistical analysis, including serve percentages, high pressure points win percentage, serve direction patterns, and more. Coaches and players can use this app to conduct real-time, micro-level performance analysis, compare players, discover patterns, and identify areas for improvement.

This app may be used simply as a score tracker. However, to generate detailed statistical analysis, the user must enter information such as serve direction, shot count, last shot type, and shot result on a point by point basis. Therefore, this app requires a high level of concentration during the match.

The frontend is a native mobile app built using React Native and Expo, and the backend is built using Google Sheets and Google Apps Script.

Repository Structure

• backend/: Server-side logic.
  • Core File: src/MicroStats.js
  • Handles data processing and statistical calculations.
• frontend-native/: React Native mobile application.
  • Built with Expo, SQLite local cache, and native UI elements.

Key Links

🌐 Project Website: gamepointanalytics.github.io/tennis-analyzer/

App Downloads

• Google Play Store: Download for Android

Documentation & Tutorials

• FAQ.pdf - Frequently Asked Questions

Sample Reports

Professional Matches

• Carlos Alcaraz vs Jannik Sinner (2022 US Open QF)
• Stefanos Tsitsipas vs Novak Djokovic (2023 Australian Open Final)
• Rafael Nadal vs Roger Federer (2017 Australian Open Final)
• Iga Swiatek vs Elena Rybakina (2023 Australian Open 4R)
• Ash Barty vs Danielle Collins (2022 Australian Open Final)
• Ash Barty vs Elena Rybakina (2022 WTA Adelaide Final)

College Matches

• Brandon Holt vs Mikael Torpegaard (2018 NCAA, USC vs Ohio State)
• Mackenzie McDonald vs Yannick Hanfmann (2015 NCAA, UCLA vs USC)

AI Insights

Detailed AI-generated insights and analysis for individual players:

• Carlos Alcaraz - AI Insights
• Ash Barty - AI Insights
• Danielle Collins - AI Insights
• Roger Federer - AI Insights
• Rafael Nadal - AI Insights
• Elena Rybakina - AI Insights
• Jannik Sinner - AI Insights
• Iga Swiatek - AI Insights

User Metrics

• 490+ downloads, 80+ installed audience, and 30-40 monthly active users

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Development (React Native / Expo)

The native mobile app lives in frontend-native/. It is built with Expo SDK 56 and React Native, and packaged into a standalone APK using the Android Gradle build system.

Prerequisites

Tool	Notes
Node.js	v18 or later
Java JDK	v17 recommended (check with java -version)
Android SDK	Installed via Android Studio
ADB	Bundled with Android SDK; ensure it is on your PATH
USB debugging	Enabled on your Android phone

Build a release APK (local, unsigned-but-aligned)

# 1. Navigate to the native app folder
cd frontend-native

# 2. Install Node dependencies (only needed after cloning or npm install changes)
npm install

# 3. Generate the release APK
.\gradlew assembleRelease

The APK is written to:

frontend-native\app\build\outputs\apk\release\app-release.apk

Build time is typically 2–5 minutes. Subsequent builds are faster due to Gradle's incremental cache.

Warning

If you run npx expo prebuild --clean (e.g. to update icons or change the package name), it wipes the entire android/ folder including local.properties. You must recreate it:

# android/local.properties
sdk.dir=C\:\\Users\\yingz\\AppData\\Local\\Android\\Sdk

Without this file, the Gradle build will fail with "SDK location not found".

Install the APK on your phone

# Connect your phone via USB, then from the frontend-native folder:
adb install -r app\build\outputs\apk\release\app-release.apk

• -r = replace (reinstall over existing version, preserving local data)
• Omit -r for a completely fresh install (wipes local SQLite data)
• Run adb devices first to confirm your phone is recognized

Change the app name

The display name shown on the home screen is set in:

frontend-native\app.json  →  "name" and "displayName" fields

After changing, rebuild with .\gradlew assembleRelease.

Check for syntax errors

# Check a single file
node --check src\screens\AnalysisScreen.js

# Check all JS files under src\
Get-ChildItem -Recurse -Filter "*.js" src | ForEach-Object {
    $r = node --check $_.FullName 2>&1
    if ($LASTEXITCODE -ne 0) { Write-Host "FAIL: $($_.Name) — $r" }
}
Write-Host "Done"

Backend (Google Apps Script)

The backend lives in backend/src/MicroStats.js. It runs entirely inside Google Sheets as a Google Apps Script web app. To deploy updates:

1. Open the Google Sheet → Extensions → Apps Script
2. Copy the contents of backend/src/MicroStats.js into the editor (replace existing)
3. Click Deploy → Manage Deployments → Edit (pencil icon)
4. Bump the version, click Deploy
5. Copy the new Web App URL if it changed and update the app's settings screen

To verify the deployed version matches your local file, search for a unique string (e.g. doPost) in the Apps Script editor — if not found, the old version is deployed.

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Troubleshooting

"SDK location not found"

Caused by a missing android/local.properties file (wiped by npx expo prebuild --clean).

Fix: Recreate the file:

Set-Content frontend-native\android\local.properties "sdk.dir=C\:\\Users\\yingz\\AppData\\Local\\Android\\Sdk"

"Gradle requires JVM 17 or later"

Your system default Java is too old. Android Studio bundles JDK 21.

Fix: Set JAVA_HOME permanently (run PowerShell as Administrator, one-time):

[System.Environment]::SetEnvironmentVariable("JAVA_HOME", "C:\Program Files\Android\Android Studio\jbr", "Machine")

Then close and reopen your terminal.

"Filename longer than 260 characters" (CMake / Ninja)

Windows has a 260-character path limit. CMake and Ninja enforce this regardless of the LongPathsEnabled registry setting. If your project path is deep, C++ compilation fails.

Fix: Keep the project in a short root path like C:\dev\tennis-analyzer\.

After moving the project to a new folder

If you move (or clone) the project to a different directory, the build will fail because Gradle, CMake, and node_modules all cache absolute paths from the old location.

Fix — full clean rebuild from the new location:

cd C:\dev\tennis-analyzer\frontend-native

# 1. Reinstall all npm packages (resolves paths to the new location)
Remove-Item -Recurse -Force node_modules
npm install

# 2. Regenerate the entire android/ folder
npx expo prebuild --platform android --clean

# 3. Recreate local.properties (always wiped by prebuild --clean)
Set-Content android\local.properties "sdk.dir=C\:\\Users\\yingz\\AppData\\Local\\Android\\Sdk"

# 4. Build
cd android
.\gradlew assembleRelease

Important

You must do ALL four steps. Skipping any one of them will leave stale paths from the old location cached in node_modules, android/app/.cxx, or .gradle build artifacts.

After running npx expo prebuild --clean

This command wipes and regenerates the entire android/ folder. You must:

1. Recreate android/local.properties (see above)
2. Run .\gradlew clean assembleRelease (the C++ cache in .cxx is also wiped, so the first rebuild is slower — about 5–10 minutes)