Most card games require you to count cards, even solitaire. As cards are revelaed you know which ones are coming and form your strategy accoridingly. This is just a battle plan for me, not cheating or anything, and good common sense too!
There some who says that it is effective and if it really is, it is a good strategy. But what even if it's effective or not, it's just like the other gambling game, luck always comes first then strategy comes next.