We've already seen that having a female wingman is likely the most powerful predictor of how easily you win over a target girl, so it's natural to ask what type of person your "pivot" should be. Basically, you're looking for a man-woman, someone who incorporates enough masculine and feminine traits that she can serve as a fluid go-between: she'll get what's going on in your head and inside the target's head, giving her a keen intuition for what she should be doing to help you get the girl.
She should be tough-minded enough to realize that playing games is necessary to win another person over, and that actions should lead closer to the goal. Still, not all such females will do -- some are too ruthless and disagreeable, and their presence will push the target girl away. And to ensure that she doesn't hog all the attention to herself, make sure she's not too neurotic -- all females are, but judge by degree.
As a rough guide, pick someone who Alias Clio calls the Amazonian Alpha. A further advantage in choosing them is that, whatever you think of their looks, you probably will not be magnetically drawn to them, as most men prefer girlier females, and so you will not be tempted to ruin your productive partnership by falling for your pivot. My best girl friend belongs to the Madonna sub-type, although I'm sure the statuesque ones would do just as well.
But what does she get out of the deal? As Clio says, these females are awfully headstrong and often too proud for their own good, so they require someone to whip them into shape. Make no mistake: she will admit to this yearning for discipline out loud, even when you didn't prompt her to say so. No other female would dare behave that way toward her, and most guys are too wimpy to do so either. That leaves you. Just make sure to remind her how much she depends on you, and she'll bear in mind that she needs to return the favor.
The only caveat is that you shouldn't be too aggressive with her, or get too into a confrontation with her -- arguing with her can be quite exhilarating! -- as this may lead her to fall for you. There aren't many guys who would steamroll right over her, and again, that's what she craves -- to not be the steamroller, for once. * Given the knack for strategizing that these women have, if she did become attracted to you, she would subtly foil all of your attempts on other girls after that. For the same reason, this arrangement works best when you are not her ideal mate in traits other than dominance.
* Don't confuse steamrolling over a person with flinging darts at them while running past at a safe distance. Women can tell from personal interactions whether you're petty and resentful or competitive and seek challenge.