[Editor's Note: The following answer was provided by John Robison, author of our book The Slot Expert's Guide to Playing Slots and one of the world's top experts on the bandits.]
I don't have access to the M's slot data — and Nevada doesn't release slot paybacks by casino — but I'm pretty sure it's you.
First, video poker. I checked vpfree2.com to see if the M has downgraded its video poker paytables in the past half-year or so. It hasn't. In Nevada, all video poker machines must deal from a fair deck. So if the M's video poker payables haven't changed and your money hasn't been lasting as long as it used to on its video poker machines, it's just a run of bad luck.
Now, slots. It's impossible to tell a slot's payback by looking at it, so it is possible that paybacks could have been lowered. The fact that the video poker paybacks haven't been lowered, however, leads me to believe that there hasn't been a change in payback philosophy and that slot paybacks haven't been reduced.
And consider this: Even if the M had trimmed its slot paybacks, it wouldn't be by enough to make everyone lose their money noticeably faster. Assuming that casinos pare down slot paybacks the same way they do video poker paybacks, the M would only lower their slot by a fraction of a percentage point or so. It would be enough to make a difference to its bottom line given the volume of play on the slot floor, but not enough that the change would have a bigger effect than luck on any individual player's results.
Finally, yes, the state can check the actual performance of any individual machine. The casino's slot accounting system captures the number of plays on each machine, the total amount bet, and the total amount paid back to players. A slot machine's manufacturer, in addition, is required to calculate the range in which the amount of money paid back to players should fall after 1,000, 10,000, 100,000, 1,000,000 and 10,000,000 plays on the machine. The state and the casino can check that the amount of money paid back to players on each machine falls within the calculated range — and investigate if it doesn't.
