There was no option on the ballot to keep the current format with the top 32 teams in a class with only one playoff bracket.
The change takes effect for the 2014 season.
Class 6A Division I will feature two eight-team districts, while Division II will have one district with eight teams and one with seven, at least for four years. U.S. Grant was recently granted independence in football. The Generals will be placed in a district officially, but won't compete in district games until at least the 2018 season.
Four teams from each district will advance to the playoffs. Districts for the 2014-15 seasons will be determined in September.
The adopted plan was initially proposed by the OSSAA's Constitution and Rules Review Committee in December, but the board voted against it. That plan used different language, splitting the 16 largest schools into what was called Class 7A, rather than dividing the class into divisions.
That language difference has some meaning, though. Under the private school rules that were implemented two years ago, private-school football teams cannot be moved into the largest class based on success rate, meaning that current 5A teams will not be moved up.
Using the previous language it could have been possible for a 5A team to get bumped to 6A, but not 7A.
Under the new plan, the three-week postseason will begin immediately after the regular season, meaning the championship games for both divisions of 6A will be played on Thanksgiving weekend, a week earlier than the current model.
Sheakley said that idea of inserting a bye week after the regular season was dismissed.
The OSSAA's contract with Oklahoma State expires after the 2013 season, so it is unknown if the championship games will remain at Boone Pickens Stadium in Stillwater.
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Timeline for the new Class 6A
Here's a look at how the new Class 6A plan will be put into action over the next 16 months:
Wednesday: The OSSAA board of directors approved the vote of the Class 6A schools to split the class into two 16-team divisions.
Late July: Around the last week of July, just before the Oklahoma Coaches Association clinic in Tulsa, the OSSAA will release the updated average daily attendance numbers for its member schools to be applied to the coming school year. In this case, the numbers released this summer will be used to set the football classes and districts for the 2014-15 seasons.
September: Coaches and administrators will meet to determine the districts for the 2014-15 football seasons. In the past, this occurred in July at the OCA clinic, but recently, the OSSAA shifted it to September to allow athletic directors and other administrators the chance to take part.
Sept. 25-26, 2014: Week 4 of the football season, the opening week of district play.
Thanksgiving 2014: The first Class 6A Division I and Division II state championship games will be played, one week earlier than previous years, since the playoffs will last only three weeks.