Gross gaming turnover (GGT) or gross turnover refers to the actual amount gambled by participants with operators such as casinos. Gross gaming yield (GGY) or gross gaming revenue (GGR) is defined as the gross turnover less the amount paid out to customers as winnings.
It has a simple formula: total bets minus total wins. This shows the amount of money that stays with the casino as a result of players' wagering activity, but before paying for any of the casino's expenses.