The soccer league consists of teams, each of which has a unique team name. Each team has one or more sponsors whose names appear on the team uniforms. Each team consists of a number of players. No player belongs to more than one team. Each player is assigned a unique Player ID when they join the league. The league records each player’s name (first name and last name) and phone number. In order to verify players ages, the league records each player’s date of birth. One player on each team is designated as team captain. Teams play each other in matches. Each match is given a unique Match ID number and is scheduled for a specific date. Each match is between two teams. The league records the score of each match. In addition, the league records, for each match, the number of minutes played by each player, as well as the number of goals scored by each player, and also the number of penalties assessed against each player. It is possible for a player to not participate in any matches. A parent volunteers serve as referees for the matches. The league assigns three referees to each match, one head referee and two linesmen. For each match, the individuals serving in each position are recorded. All of the referees are assigned a unique Referee ID number when they first register with the league. The league records each referee’s name (first name and last name) and phone number. Each new referee is assigned to one experienced referee as a mentor. Not all of the experienced referees serve as mentors, but those that do can mentor more than one new referee. Matches take place at soccer fields. Each field has a unique name. The league records the name and address (street, city, state, and zip) of all the fields where it stages matches. Each match, occurs at a single field at a time. The fields host multiple matches Some fields are closed when undergoing renovations with no matches scheduled.