TwentyOne: Blackjack Trainer
No in-app products collected for this app.
| Rating | |||
|---|---|---|---|
| United States | 100%2 | 5.00 | |
| Antigua And Barbuda | <1%0 | — | |
| Anguilla | <1%0 | — | |
| Albania | <1%0 | — | |
| Armenia | <1%0 | — | |
| Angola | <1%0 | — | |
| Argentina | <1%0 | — | |
| Austria | <1%0 | — | |
| Australia | <1%0 | — | |
| Azerbaijan | <1%0 | — |
Description
TwentyOne is a clean, focused blackjack basic-strategy trainer. Learn the mathematically correct play for every hand, then drill it until it's second nature — in a calm, minimalist interface with no ads and no clutter.
WHY TWENTYONE
Basic strategy is the proven, optimal way to play every blackjack hand. TwentyOne doesn't just show you a chart — it computes the correct play for your exact table rules and helps you commit it to memory through fast, focused practice.
THE STRATEGY CHART
The complete chart for hard totals, soft hands, and pairs
Color-coded for Hit, Stand, Double, Split, and Surrender
Tap any cell to see the expected value behind every option
Recomputes instantly when you change the rules
PRACTICE THAT STICKS
Deal a hand, choose your action, and see the correct play right away
Modes: Random, Hard Totals, Soft Hands, Pairs, and Most Missed
"Most Missed" automatically resurfaces the hands you get wrong
Track your accuracy, streak, and performance by hand type
PLAYS BY YOUR RULES
Real tables differ, and so does correct strategy. Configure:
Number of decks (2, 4, 6, or 8)
Dealer hits or stands on soft 17 (H17 / S17)
Double after split, double rules, and late surrender
Resplit aces, hit split aces, and more
The chart and every practice answer adjust automatically.
TWENTYONE PRO
Take your training further with a single one-time purchase — no subscriptions, no ads:
Expected value on every hand — see the full EV breakdown behind your decision after each practice hand, not just in the chart
Card Counting Trainer — master the Hi-Lo system with four focused drills:
Card Values: flash through the +1 / 0 / −1 tags until they're instant
Running Count: keep an accurate count as cards are dealt
Deck Countdown: race through a full deck down to zero
True Count: convert running count to true count on the fly
Everything else in TwentyOne is free.
MADE TO LOOK GOOD
Minimalist design with crisp, simple cards
Full light and dark mode
Three app icons to choose from
No ads, no accounts, no tracking — works offline for all training
TwentyOne is for study and entertainment. It teaches optimal decision-making and involves no real-money play and no wagering.