In Texas, the schools mutually agree on playoff sites. Since early round games are, quite often, top teams playing teams with losing records, the ‘top’ team will host. Many times, they’ll agree to do a “home & home” thing, after a coin toss. The winner of the toss gets to choose which school hosts this game, then, if they meet in playoffs again in the coming years, the other school will host. But, many schools will, indeed, agree to meet at a more centralized site, more due to travel distances than ‘home field advantage’ issues.
It takes 5 playoff games for 11-player teams to reach their championship game (5 classes x 2 divisions each = 10 games), 4 playoff games for 6-player (1 class x 2 divisions = 2 games; they get an extra week off before the championship games). All 12 championship games are played at Jerry World (‘affectionate’ name for Cowboys Stadium). 3 games per day x 4 days (Wednesday thru Saturday), in mid-December. Temporary boundary lines, hash marks, and goals are set up (on the NFL field) for the 6-player games, both of which are played first on the Wednesday. Then a ‘cleanup’ crew eradicates the 6-player markings, and removes the temporary goals, and the first 11-player game is played that evening. Then the rest of the games are played Thursday thru Saturday.
Quite an operation.