Blackjack Trainer

A complete product, shipped solo, with the depth a serious player needs. Proof I finish things — even on nights and weekends.

Built with AI assistance but the product is pure deterministic domain modelling — counting, EV math, spaced-repetition. The AI angle is the build process, not the product.

React 19 + Vite 6. Pure-function game engine with strategy.test.js invariants. 17 modes. All client-side; works offline.

Vite build, Vercel hosting, zero backend. State in localStorage. Static and cacheable — the kind of deploy that's impossible to break in production.

Deep domain modelling — Hi-Lo, KO, Omega II, Illustrious 18, rule variants, Wonging — shipped as a working tool for a specific advanced user.

Play it live

Most blackjack tools are flashcards. This is a full simulator with the rules a counter actually cares about — H17/S17, DAS, RSA, surrender, deck penetration, bet spread — plus Wong-in/out and the Illustrious 18 deviations.

The engine is a pure-function module. No React imports. The UI is one consumer; the math is testable on its own.

Engine

src/engine/Eight pure-function modules. Zero React imports.

card.js

Card primitives

game.js

Game state machine — deal, hit, stand, double, split, surrender, insurance, resolve

strategy.js

Optimal-action lookup · invariant-tested

counting.js

Hi-Lo + KO + Omega II · true count · bet rec

probability.js

Odds and EV math

spacedRepetition.js

SRS for strategy drills

sessionHistory.js

Session tracking + CSV export

sound.js

Audio feedback

Modes

Free play · Strategy chart · Strategy drill (SRS) · Count practice · Counting tutorial · Counting panel · Shoe visualizer · Bet spread driller · Illustrious 18 · Gauntlet · Wonging · Multi-hand · Team play · Leaderboard · Education panel · Dashboard · Configurable rules.

Rules

Decks 1–8 · H17/S17 · DAS · RSA · Surrender · Configurable penetration · Min/max bet · Counting system · Hint visibility.

Stack

React 19 · Vite 6 · Pure CSS · Recharts · @vercel/analytics. State in localStorage. No backend. Works offline.

17 modes · 19 components · 9 engine modules · ~6.1k lines.

← TripOS