A: What’s all the excitement about this tennis match in town?

B: Well, it’s because the former champion is participating in the tournament, looking to settle an old score with the young player who dethroned him two years ago.

Note: This idiom means “to get vengeance on someone for a past wrong or grievance, to punish someone for causing one harm or misfortune in the past.” It is a 17th century English phrase, which originated from a bill that was called “score.” If you settled your score, it means that you have paid or cleared up your bills for what you owed in the past.