Was reading an article and saw that it recommended practicing counting triple card counting combinations(ie 3 cards at a time).

Was wondering if that practice is targeted toward some specific situation(s)?

I know that practicing two card combinations is mostly for the initial deal, to count down the table in pairs, and single card is for situations outside that.

Guess I'm wondering if triple is supposed to be aimed at Heads-Up play against the dealer or is it because most hands end in 3 cards or less? Or is there something else I'm missing?