Goal Minutes Sporting Index (GMSI) is a measure of the total amount of time that a team spends in the opposition's half of the field during a match. It was developed by Sporting Index, a British sports betting company, as a way to predict the outcome of soccer matches based on statistical analysis of game data. The GMSI is calculated by dividing the total number of minutes spent in the opposition's half of the field by the total number of minutes played. A higher GMSI score indicates that a team has had more possession and created more scoring opportunities than their opponent.