Works for all
I am starting to use the halves count strategy.Is it more benefial to play single deck,2 decks,or 6 decks?
All else being equal, it is better to play fewer decks, regardless of which count you use. However, all else is rarely equal.
Assuming you don't make mistakes, halves will increase your performance for most any game. My guess, however, is that it will also increase mistakes you make and playing fatigue.