Inside Track

Inside Track is a betting shop for thoroughbred horse races. Inside Track Betting (ITB) machines line the walls of these establishments, which can be found in various locations throughout San Andreas in 1992 and Vice City in 1984. The player can bet money on horse races in Grand Theft Auto: San Andreas, but not in Grand Theft Auto: Vice City Stories. In the mission Small Town Bank in GTA San Andreas, Catalina, together with protagonist Carl Johnson, robs the Montgomery branch of the betting shop for money, and later, as a result, was chased by police. Luckily, they were able to get to Catalina's hideout in Fern Ridge to lose the cops.

Branches in GTA San Andreas

 * Mulholland Intersection, Los Santos
 * Montgomery, Red County

Betting Trick

 * Taken from Forum:Get Rich Quick Betting Trick

A simple way to ensure you never lose is to save before you bet. This way if you lose you can just reload your save game. If you gamble all your money in one go, then if you win you will gain a large amount of money.

To ensure that you eventually win, you should bet on the same horse every time. Statistically, this horse will eventually win, and should not take more than around 5 attempts. Once you win, save the game again and you can repeat if required.

For this trick to be worthwhile, you should save at a location close to the betting shop. The closest safe house and Inside Track Betting Shop together are the Jefferson Safehouse in Jefferson and the betting shop in Downtown Los Santos under the Mulholland Intersection. However, the Glen Park safehouse has no garage, so you'll have to steal a vehicle outside.

Note
Using the betting shop for becoming rich quickly takes away the fun of playing the game become money become no issue for the player, but most missions reward the player in money only.