In chess notation, the symbol “+!” represents a very strong move. It is used to indicate a move that is considered to be even stronger than a move that is annotated with the symbol “+”. The “+!” symbol is used to emphasize the importance of a particular move in a chess game. This notation is used by chess commentators, annotators, and analysts to give a deeper understanding of the game to the audience. The “+!” symbol is often used to indicate a move that leads to a decisive advantage for one player, such as a decisive tactical blow, a decisive positional gain, or a winning endgame. Understanding the use of the “+!” symbol is important for chess players who want to improve their understanding of the game and to become better players.