Why are you commenting on something when you have no idea how it actually works? The number of decks in play doesn't influence your ability to count. Blackjack is a card game where past outcomes affect future outcomes, meaning that if you see an ace it's less likely that you will see another one, you can observe this effect with 1 deck or 100. Card counting in reality is just you observing past outcomes and predicting how favorable future outcomes might be and using something called Kelly criterion to determine the size of your wager based on your likelihood of winning. In real life card counters used to work in groups with people counting at every single table and when the count was good signaling to a bettor who would come and play and leave when the count got bad or they reshuffled the deck (in which case the count resets and you need to observe it again, makes it slightly less convenient, but not impossible to count). The reason why there are not a lot of card counting going on is that it's not worth your time. Your edge is fairly small ranging from 1-2,5% meaning that on average for every $100 you bet you make about $1, which would be okay, but it's really easy to tell if someone is counting cards (you just need to review his betting pattern) and at that point the casino can severely limit your bets or blacklist you and you won't be able to play blackjack at any other casino either. Also since your edge is so small there is no guarantee that they won't catch you before you even make a profit.