Sigma Derby is an electro-mechanical horse race used for gambling manufactured by Japanese manufacturer Sigma Game Inc. and introduced in 1985. Up to ten players can buy in with quarters and place bets on the five horses; a quinella of two horses in any order pays out according to the odds. The house has roughly a 10-20% advantage, depending on the machine.
After the closing of the New Frontier Hotel and Casino, there are only two remaining Sigma Derby machines in Las Vegas. One on the Strip can be found at the MGM Grand Las Vegas as of April 2015. The other is at the D Hotel in Downtown Las Vegas. There are also two Sigma Derby machines near the sportsbook area of the MontBleu casino/resort in Stateline, Nevada, and another machine at the Royal River Casino & Hotel in Flandreau, South Dakota.