When do lineups become official?

The lineups become official after the lineup cards are exchanged and accepted by the umpire during the pregame conference. This step is crucial as it ensures that both teams have their starting players recognized and that the game officials have all the correct information necessary for the match. The process involves sharing the details of each team's roster with the umpire, who verifies the lineups' accuracy before the game begins. Once this exchange and acceptance occur, it solidifies the lineups, making them official for the purposes of the game.

Other steps in the process, such as the coaches presenting lineups to the umpire or announcing "Play Ball," do not fully formalize the lineups. Presenting lineups or exchanging cards alone does not constitute an official confirmation until the umpire has accepted them. This emphasizes the importance of the umpire's role in validating the players participating in the game.