Sigma Derby is one of those cult games that's a QoD FAQ and we've actually addressed it several times over the years (8/9/09, 7/28/07, 5/15/05), each time with diminished results in terms of where you can find it.
For anyone unfamiliar with it, Sigma Derby is an endearingly low-tech electronic horse-racing game with a horrible house edge (12%-15%) that was often found close to the race and sports book. Up to 10 people could play at any time and everyone sat around the miniature "track" as five mechanical horses competed in race after race. The minimum bet was 25ยข and the only bet you could make was a "quinella," i.e., choosing which two horses would finish first and second, in either order.
Go back a decade or so and Derby was available in at least 10 casinos around Las Vegas, including the Hilton, Orleans, MGM Grand, New York-New York, Caesars Palace, Imperial Palace, Riviera, Bally's, New Frontier, Excalibur, and Luxor (which had racing camels instead of horses). One by one they all disappeared, however (as did one of the casinos) and for some time the only remaining game in Las Vegas is to be found near the race and sports book at the MGM Grand. Yep, it's still there -- we just called once more to check.
What became of the other machines, we know not, unfortunately. We happened to be researching a similar question to this when the New Frontier ditched its machine, and we tried to find out what happened to it when it disappeared, but neither anyone at the hotel nor Sigma could tell us. Most likely they were either thrown out or perhaps went to members of staff, as sometimes happens with other casino fixtures and fittings, like table felts.
The reason for its demise is not so hard to fathom -- the game takes up a fair amount of space and was evidently just not an economically viable proposition in terms of profit-margin-per-square-foot. We figure that having the largest casino floor in Vegas affords the MGM Grand the luxury of giving up a little space to this old favorite.
One interesting note, however, is that a Swedish company called SolidIcon has developed two electronic games called Triple Towers Horse Race and Triple Towers Greyhound Racing, that look to be similar to a hi-tech virtual version of Derby, and has teamed with leading slot manufacturer IGT to introduce these games into the US market. Right now, no Las Vegas casino is carrying either of them, so we haven't had a chance to see the games in action, but IGT told us they hope to have them here in the near future, so we'll keep you posted. In the meantime, here's a list of the locations which already have Triple Towers Horse Race on property:
