Game is much more than pick-up artistry. It may have been the PUAs who hacked the female brain, but what they discovered can be applied to all male-female relationships. In evolutionary psychology, women are programed to always be looking for somebody better. You can only stop this if you are someone she perceives as being clearly a high value guy. Some of this can be faked, but mostly you just gotta be better. Women have great bullshit detectors, but they were for an earlier time and a vastly different environment.
When you really become a better man, you don't even care so much if she leaves because you can get another one easily. Just don't put them on a pedestal. I don't care how hot she is, there's a dude somewhere that's sick of putting up with her shit.
Keeping a woman is simple, IMO: learn to be a better lover. If you ain't giving her orgasms, not a goddamn thing else matters, because like men, women get frustrated when they don't get orgasms. If you jump on top, grunt like an ape, couldn't even be bothered to put deodorant on, and finish in 2 minutes, she's going to have to do the orgasm bit herself, which means what the fuck good are you in that very important department? Being a good lover and giving orgasms brings sex from a detriment (having to work to get you off) to a bonus (getting off without a two minute hump on the shower head). All this means you get laid more, so you're happy and more attentive (which she likes), and she doesn't need to look to her vibrator (or the pool boy) for her needs. Positive feedback loop.
The problem is, women are more sensitive to the emotional mood of the relationship, so if you're not treating them right outside of sex, they won't be able to get off during sex. Unlike men, women generally cannot get off with people they've started to loathe, and once the loathing starts, you're fucked, but in all the wrong ways, and it's time to end the relationship.
There is no programming, women are not machines, they are not cryptic, their brains cannot be hacked. That's all stuff people who don't understand women say. The truth is, they're almost as simple (or as complex, depending on how you want to look at it) to please as men are, they just require somewhat different things (not just sex but it is a much bigger part than men give it credit for), and you need to learn what those are and do them if you want to keep her. If you don't do that, she WILL look for better, but that's not any sort of programming. That's just common sense.
Remember: nice guys finish last...in bed! Do her first, and she'll put you first.