Initially, in American bookmakers, the names of the horses and the coefficients for their victory were recorded on the board (board), in other words, the nicknames of the horses were entered on the board (on the board). If for some reason the bookmaker does not want to accept bets on any sporting event, then she writes “Off the Board” instead of betting odds. In other words, the bookmaker struck out bets on this sports competition from its “board”.