Warning: Long, but detailed post on how the UIL sets up classifications, districts and football playoffs.
The UIL uses a set system for how high schools are classified and set into districts for UIL competitions/games. There is also a set system for playoffs. To the outsider looking in, this can be incredibly confusing. Once you understand the systems, it makes perfect sense. I will do my best to break it down for anyone wanting to understand the systems.
First, the Texas University Interscholastic League (aka UIL or The UIL), uses each high school's enrollment to divide them into a classification; with 6A being the largest schools in the state and 1A being the smallest.
First, the UIL determines how many schools will be in each classification. These numbers are based on the number of high schools in the state who participate in UIL competitions (sports, fine arts, etc.). Because some schools don't participate in every sport, these districts can be different from one sport to the next. Sometimes, the UIL will announce these numbers in advance.
In each odd calendar year, the superintendent of each district (or his designated representative) submits the enrollment of each high school campus on the last Friday in October (we are currently using the enrollment numbers from Friday, October 30, 2015). This is how many students are enrolled that day, not the attendance. The UIL has formulas for schools who do not house four grade levels or whose students participate in work-study programs. Once these numbers are submitted, the UIL enters them into a spreadsheet and orders them with the largest school at the top and the smallest at the bottom. They then go down the list until they reach the predetermined number of schools in 6A and draw a line. Every high school above this line will be a 6A school. Next, they do the same thing for the number of schools for 5A, draw the line, and everyone between the two lines will be 5A. This continues to the bottom of the page. Sometimes, the UIL will make these cutoff numbers public. Since many school publicly announce their enrollment number on the UIL Snap Shot Day, at the time of the UIL's cutoff number announcement, many will know into which classification they will be grouped for the upcoming redistricting.
Some schools may petition the UIL to change their classification. There is a process for this, but I don't think I've ever seen it used in southeast Texas. (Edited to add: La Marque discussed this one year and may have used it. Houston ISD is reported to have used it also.)
The next step is to create the districts. These districts are based on classification and geography. The UIL tries to keep all the high schools within a school district together, for example, all 5 of CCISD's high schools are in district 24-6A; and they try to keep travel times between schools within a district to a minimum. Districts generally consist of 7 or 8 high schools. If a school district has more high schools than that, their schools will be split among multiple districts. The new districts will be announced in February of even calendar years and will go into effect at the beginning of school that same calendar year. Districts are set for 2 year intervals.
We are currently in the middle of the redistricting process. Enrollment Snap Shot Day was Friday, October 27, 2017. We are awaiting the official announcement of cutoff numbers, through many sports publications have already made their predictions. In February, we will learn who will be in each district for the next 2 school years (starting in August of 2018).
FOOTBALL PLAYOFFS:
If you are looking for information on playoffs in other sports, I'm sorry, I just don't know how similar or different they are to the football procedures.
This information is true this year for 5A and 6A. Next year, the rules for 5A will change. So, for the 2017 football playoffs, here is the procedure.
At the end of the regular season, the teams in each district are ranked, with the team with the best win/loss record (for district games) at the top, and the team with the worst win/loss record at the bottom. The top 4 teams in each district will be in the playoffs. Of those 4 teams, the two teams with the largest enrollment (using October 2015's numbers) will go into the Division 1 (D1) bracket and the teams from the 2 smaller high schools will go into the Division 2 (D2) bracket. In D1 and D2, the team with the better record will be considered the top seed. The second team will be the second seed. Neighboring districts will play each other with the top seed from each district hosting the second seed from the neighboring district. The location of the game can be at the home stadium for the top seed team or a neutral site. The winner of this game will move on to play the winning team from another local match up. The way the brackets are set up, if the two teams from the same district win all their playoff games, they won't face each other until the fourth round of the playoffs. Once a team loses, they are out of the playoffs.
Example:
District Colorful-6A results
Team Win Loss Enrollment (Oct. 2015)
Red 7 0 2418
White 6 1 2275
Blue 5 2 2358
Green 4 3 2479
Purple 3 4 2199
Orange 2 5 2501
Yellow 1 6 2413
Gray 0 7 2251
Realistically, there will be ties, but for this example, I'm keeping it simple. In this example, Team Red, White, Blue, & Green would make the playoffs. Due to enrollment numbers, Red and Green would be D1 with Red being the top seed and Green being the second seed. White and Blue would be in the D2 bracket with White being the top seed and Blue being the second seed.
Let's say the neighboring district is Animal-6A Their end of season results were:
Team Win Loss Enrollment (Oct. 2015)
Dog 7 0 2318
Cat 6 1 2202
Horse 6 1 2459
Mouse 5 2 2640
Rabbit 4 3 2274
Moose 2 5 2365
Crocodile 1 6 3102
Bear 1 6 2385
For this district, Team Dog, Cat, Horse, and Mouse would be in the playoffs. Due to enrollment numbers, Mouse and Horse would be in the D1 bracket and Dog and Cat would be in the D2 bracket. The top seed for D1 would be Horse and Mouse would be the second seed. For D2, Dog would be the top seed and Cat would be the second seed.
Since these are neighboring districts, the first round of the playoffs would be Mouse at Red, Green at Horse, Blue at Dog, and Cat at White. Red, Horse, White, and Dog could play these games at their home stadiums, or they could be played at a neutral site.
After the first round of playoffs, every game is held at a neutral site. It is not unusual for coaches to talk to all the coaches they might face in the coming week or two to set up tentative sites and dates/times for playoff games. They don't want to do things too early, because that's more tentatives to work out, but too late and all the good stadiums are booked.
I hope all that is helpful. If you have any questions, you can ask me or Google. The UIL website has lots of information, but it can sometimes be hard to navigate.
