21 is a magic number, it’s the age when you get to buy your own beer (if you’re in the US) or the Holy Grail for those that play Blackjack. John Scarne names this game (in his book “New Complete Guide to Gambling” to be the most widely played game in the casino world and you can imagine the interest it gets in the mobile world as well, with over 24,000 related Android apps & games in Google Play alone.

For those of you that don’t know what Blackjack (also named 21) is when played in a casino, a quick guide:

  • it is played with one or more decks of cards (52 in the pack)
  • The goal is to reach 21 by summing the “value” of the cards you have in your hand, or at least get more than the dealer without exceeding 21
  • “Face cards”, meaning Kings, Queens and Jacks, count as 10 points. An Ace can be either 1 point or 11 points, depending on the choice of the player/dealer. All other cards have their own value (i.e. the card 8 has a value of 8)
  • In a casino you play against the dealer, even if other players are at the table as well (you don’t compete against those, but it’s important to know what cards they get)
  • Game starts with 2 cards and you can choose to get “hit” after that, meaning you get another card for each round (you can also pass if you are close to 21). If you reach 21, you’ve won (unless it’s a tie), if you go over 21 you’re bust (you lose), but in most cases one of the players gets as close to 21 as possible exceeding the other player’s score.

Due to its popularity and predictability, it attracted brilliant minds into the game that used card counting methods or Blackjack schemes to beat the casinos. The MIT Blackjack team was a real team of students from Harvard and MIT that used card-counting techniques for almost 20 years to beat casinos around the world. They’ve inspired the movie 21 (you might remember Kevin Spacey from the movie, as other actors were poorly chosen) and skyrocketed the interest of players around the world on card-counting methods and Blackjack systems.

Blackjack Trainer is an app for Android devices that brilliantly takes onto this task of helping you develop your own Blackjack system to beat the casino. It’s one of the few apps of this genre that takes into account the fact that at a given table you’re playing against the dealer but also have to consider what cards additional players at the table receive too. You can tell that this app was developed by someone who knows the game very well, as it’s the case here, because the author of Blackjack Trainer developed previously a desktop game as well, to train himself in card-counting strategies en route to Las Vegas – I invite you to read the full interview at the end of the description for more insights.

You can see BlackJack Trainer in action in the following video:

Blackjack Trainer has multiple options that allow you to perfect your playing skills and develop strategies based on real-life scenarios:

  • Play as the 1 – 5 player. You can play as one of the 5 players that will be at the table, if you select one player all others will be set to automatic playing mode (AI plays for them).
  • Set number of decks in the shoe. If you haven’t played in a casino before you might consider the word “shoe” literally, but a “dealer shoe” or dealing shoe is the box where dealers hold the deck of cards. With BlackJack Trainer you get to select how many deck of cards to be used in a single game (by default 5 decks of cards).
  • Set player’s starting bank. You can choose the amount of chips to start the game with, preferably higher to continue playing the game longer and just keep practicing your method.
  • Set table min/max. You can set the minimum/maximum amount allowed for a bet at the table.
    BlackJack Trainer's betting system.

    BlackJack Trainer’s betting system.

  • Show count statistics. You see throughout the game current count statistics based on the count method selected.
    Count statistics that show up in BlackJack Trainer.

    Count statistics that show up in BlackJack Trainer.

  • Get advices. My favorite part is the suggestion you receive when playing a game. You get suggestions such as Hit or Stop, depending on what your cards sum up to and the strategy selected. I say it’s my favorite as it is quite easy to just follow the advices of an automated system, however if you’re training to learn card-counting, then your eyes should be focused more on the count statistics.
  • Choose from several count methods. You can choose from 3 different count methods: High-Low (the most popular counting method), Canfield Expert (a method best suited for single-deck BlackJack) and Silver Fox (recommended for beginners).
  • Choose from several strategies including Basic Strategy. 5 strategies to choose from: High-Low Multi-Deck, Basic Single Deck, Basic Multi-Deck, Aggressive Multi-Deck and Smart Multi-Deck.

Card counting is the most important part of this app, so you have to understand how that works. What happens is that basically for each card available a positive, negative or zero value is assigned. So when a card is dealt, the counter is adjusted by its value. Low cards increase the counter (+1 value), while high cards decrease the counter (-1) – cards 7, 8, 9 have a zero value. For low cards you increase the value as basically the probability to receive a high card increases. This is the High-Low counting method and there are much more advanced counting methods.

The game is free and you can download it from Google Play: Download BlackJack Trainer

The developer of BlackJack Trainer took the time to answer some of our questions in a very interesting interview that I invite you to read below:

Q: Can you share some information about yourself with our readers?

A: I am a geek, tinkerer and lazy, basically the recipe for a programmer.

Q: How did you come with the idea to create your app, what inspired you?

A: I love to gamble and Blackjack is a game that I greatly enjoy. I wrote a windows desktop application several years ago and would always play it on my laptop on the flight to Vegas to brush up on blackjack strategies and my card counting skills. One day I thought it would be more convenient to use my phone as it was more portable but found the existing apps to be lacking, mainly due to the fact they were one player verse the dealer when in a real game it is a table full of people and counting is more difficult. So I built my own app to fill this void.

Q: How long did it take from that idea until the first public release?

A: I started the initial idea about 6 months ago, after several iterations I felt comfortable enough to take the app public.

Q: Have you developed other apps or is this your first one? Do they target only the Android market or others as well (i.e. iOS)?

A: I have developed desktop applications, web applications and mobile websites but this is my first foray into app development.

Q: With hundred of thousand of apps in the appstore, how do you make people aware of your app?

A: This is the magic question and one that I am still learning. If anyone has insights they want to share, I will gladly listen.

Q: What future plans you have for your app (new features, …)?

A: I have several more counting counting methods and playing strategies that have not been ported to the app. I plan on releasing them in future updates. I am also working with designers to offer a cleaner UI.

Q: What popular apps are an inspiration for you as a developer and why?

A: I would say Flaming 7s slots by leetcom. The interface is simple and clean and it gives a pretty accurate casino slots experience.

Q: Have any tips/advices for other developers that want to start working on an app? Any tools that you consider to be a must?

A: There are a lot of frameworks and SDKs that can help, but I would suggest that a new developer write a native app first so they truly understand what is going on under the hood. After that find a framework or SDK that works for you and take the time to learn it.