What can a referee use to maintain order during a match?

The use of a yellow card for cautions and a red card for expulsions is a standardized and effective method for referees to maintain order during a soccer match. The yellow card serves as a formal warning to players for misconduct, which alerts them that further infractions can result in more severe consequences. When a player receives a red card, they are immediately ejected from the game, reducing their team's ability to compete effectively and emphasizing the seriousness of their actions. This system of carding promotes accountability and discipline, helping to deter unsportsmanlike behavior on the field.

In contrast, a warning system may not carry the same weight or urgency as a card, while a time-out feature is rarely utilized in soccer, as the game is designed to maintain continuous play. Self-regulation by players can be ineffective, as it relies on individual discretion, which can lead to inconsistency in conduct and discipline within the match. Therefore, the formal card system is essential for a referee to ensure that the game's integrity is upheld and that all players adhere to the rules.