ACF format
The ACF format was designed by Robert Meredith and adopted by ACF for its official tournaments. The ACF format is used at almost all collegiate tournaments and many high school tournaments which are otherwise not connected to the ACF organization.
Format
The ACF game consists, simply, of twenty ten-point tossups with thirty-point bonuses. There is no clock and there are no powers. See the ACF rules for the full description of the format.
Almost all collegiate tournaments, both academic and trash, now use this format (though some use the so-called mACF format, which adds powers). It has also become a popular high school format in many areas, and is used for such notable high school tournaments as the GATA State Championship, the Vanderbilt ABC, the GSAC, the Maryland Spring Tournament, the Yale BHSAT, and the Thomas Jefferson winter tournament.
Finals Format
One of many ACF innovations designed to promote fairness in the game is the "ACF finals format." Used at all official ACF events and many other events, this finals format involves awarding a tournament title outright to a team which is two or more games ahead in the standings of the second-place team at the end of the tournament proper; playing a one-game, winner-take-all final if two teams are tied; and playing an advantaged final of up to two games, in which the team that is ahead needs to win only one game but the trailing team needs to win two games, if the first-place team is exactly one game ahead of the second-place team.
The ACF finals format was first used for tournaments in 1994 upon the suggestion of Gaius Stern.
Further information is available here.