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general::
Applying to all the individuals in a group, as in They promised us an across-the-board tax cut, that is, one applying to all taxpayers, regardless of income. This expression comes from horse racing, where it refers to a bet that covers all possible ways of winning money on a race: win (first), place (second), or show (third). The board here is the notice-board on which the races and betting odds are listed. Its figurative use dates from the mid-1900s.
American Heritage Idioms