Who doesn't love Sigma Derby! Sitting at this machine in the MGM Grand was one of the highlights our our trip to Vegas. Playing is simple. You just put quarters in the machine and bet on the combination of horses coming in first and second. This is a great way to gamble and drink for free for hours without losing too much as long as you bet smart. I usually put one quarter on the long shot, two on the best odds, and one more on a medium odds combo and play for hours without losing much (or possibly even winning some). The last time we played, I hit one of the long shots and left with more money that we started with. I also got some free beer and left with a smile on my face. This is my favorite gambling machine anywhere. I've also spent a few quarters on the Sigma Derby at the Mont Bleu in Tahoe and love them just as much.