Complex sentence: In a league tournament, when two or more teams finally have same number of matches won/lost to their credit, it is difficult to declare which one is a better team among them and we say that the teams are tied up.
Split into simpler sentences: In a league tournament when two or more teams finally have same number of matches won/lost to their credit. It is difficult to declare which one is a better team among them and we say that the team are tied up.