Card Counting Systems
From beginner-friendly balanced counts to expert-level fractional systems, Protocol 21 supports every major card counting method. Choose your path and start training.
Beginner Systems
Start your card counting journey with these proven, easy-to-learn systems. Perfect for new advantage players.
Hi-Lo
Master the famous Hi-Lo card counting system with Protocol 21. The world's most popular balanced counting system, explained and trained with casino-grade drills for iOS and Android.
KO (Knock-Out)
Learn the KO (Knock-Out) card counting system — the easiest way to gain a casino edge without true count math. Protocol 21 is the best KO trainer app for iOS and Android.
Red 7
Learn Arnold Snyder's Red 7 system — an easy unbalanced count that removes true count math. Protocol 21's color-sensitive drill mode makes Red 7 the easiest system to learn on mobile.
Advanced & Expert Systems
Ready for a challenge? These Level 2 and Level 3 systems offer higher accuracy at the cost of increased complexity.
Zen Count
Master the Zen Count — a powerful balanced Level 2 system for serious blackjack players. Protocol 21 provides the custom multi-value drills you need to run Zen Count at casino speed.
Omega II
Master the Omega II card counting system — the most accurate Level 2 system for professional blackjack. Protocol 21's advanced drills support multi-value card counting and Ace side counts.
Wong Halves
Master Wong Halves — the most powerful and most difficult card counting system ever developed. Protocol 21 is the only app that supports fractional half-value drills for expert-level training.
System Comparison
Not sure which system to learn? Compare the key features of each counting method.
| System | Difficulty | Type | Best For |
|---|---|---|---|
| Hi-Lo | Beginner | Balanced | Level 1 |
| KO (Knock-Out) | Beginner | Unbalanced | Level 1 |
| Red 7 | Beginner | Unbalanced | Level 1 |
| Zen Count | Intermediate | Balanced | Level 2 |
| Omega II | Advanced | Balanced | Level 2 |
| Wong Halves | Expert | Balanced | Level 3 |
Ready to Start Counting?
Download Protocol 21 and practice any counting system with casino-grade drills. Available free for iOS and Android.