How do casinos "tighten" video poker machines?

With the recent addition and quick subtraction of "good video poker" machines at Four Queens, I was wondering which casinos have been the most consistent over the years and decades of having and keeping "good video poker" machines. Specifically, I'd be interested in Full-Pay Deuces Wild video poker, but casinos with historically good machines are welcome.

Players club tracking has become so sophisticated, I — and I assume many other readers of your fine Question of the Day — have found ourselves in casino crosshairs because of our advantage play. I play only JoB 9/6 and DW44. My favorite local casino has not only cut my weekly cash from $45 to $5, they have actually cut my percentage comp return, which I know only because I keep my own detailed records. Once you’ve been "marked" like this, is there any way to get back into their good graces?

I’ve always been fascinated that someone could make their living gambling, so I was wondering how changes over the past 25 years have affected the number of professional video poker players in Las Vegas. I would guess that professional play on the Strip has long become untenable, but has play off the Strip also tightened in any way to significantly reduce the number of people who make a living playing VP? If so, could anyone estimate how much of a % decrease there has been in that time frame?