If I tried this and got your result, I would have left after the fourth machine. I have done that kind of thing many times. It's funny, not really if you want to keep playing, how often you get up 20-30% or more within 1/2 hour. I do this and leave all the time. I used to just play and play after getting up quickly, mainly because I just wanted to keep playing slots. My wife and I both play and thankfully we agree on this, and it's hard, but we just force ourselves to leave up a couple hundred. I play horses and a number of times I played a pick 5 bet usually around $200, and went to the slots and covered the bet and left. No one ever lost money at the casino when they left while they were ahead.