It was however still possible to play 1-on-1 versus fights. The Tag system even applied to the Team Battle mode. It was the first game to implement several features, the most obvious being the Tag System, which allowed a player to select two characters that form a tag team, who are then able to fight against other tag teams, be they player or AI controlled. Tekken Tag Tournament (also called TTT) is the fourth game in the Tekken series.