Yeah it all really depends on the person you are performing for. If the spectator doesn't listen and just digs their fingers down lower in the spread and grabs a card..yeah not gonna go over so well. The classic force use to be the only force I ever used and then I haven't used it in a while and now ...bleh I'm kind of only decent at it. It takes a bit of muscle memory to know exactly where the card is your spreading and coordinating the spreading with the timing of their finger. I never used the "touch the card to the spectators finger" idea I always timed it.