It’s high school football playoff time, with new teams trying to crash the championship party

For the first time in years, the Southern Section and City Section football playoffs will start with a hint of uncertainty as to which team finishes as champion in the highest divisions.

Since 2016, every Southern Section Division 1 championship game has been won by St. John Bosco or Mater Dei. This season, Mater Dei has losses to Corona Centennial and Santa Margarita. St. John Bosco’s invincibility was punctured with a 35-31 regular-season finale loss to Mater Dei.

“We have to pick ourselves up. We’re still a good football team,” St. John Bosco coach Jason Negro said.

Then there’s Sierra Canyon, which is 10-0, has the best defense anywhere with five shutouts and still gets ranked No. 4 by a computer that decides Southern Section playoff pairings. Do you think the Trailblazers have something to prove?

“We’re kind of the new kids on the block,” coach Jon Ellinghouse said. “We’ve gained some valuable experience. We have a team that belongs on the stage.”

Sierra Canyon is opening the playoffs in two weeks, hosting Santa Margarita as part of an eight-team Division 1 bracket released on Sunday. St. John Bosco is seeded No. 1, Corona Centennial No. 2, Mater Dei No. 3. The championship game is set for Friday, Nov. 28, at the Rose Bowl.

Sierra Canyon will be facing a gauntlet of Trinity League teams, something it has prepared for in the last two seasons by playing Trinity teams in nonleague and playoff games. That Santa Margarita matchup features perhaps the two best defenses in the Southland and six of the players in the game are USC commits.

Don’t forget the best quarterback in Southern California comes from No. 6-seeded Mission Viejo. Ohio State commit Luke Fahey passed for a school-record 569 yards this past week against Los Alamitos. And the Diablos have wins over Santa Margarita and San Diego Lincoln as part of a 9-1 record but injury problems on defense will make it a tough task to get by defending champion Mater Dei.

And Centennial coach Matt Logan, who has passed the 300-win plateau, has his team ready for the big games ahead with an offense that has scored 59 and 60 points, respectively, the past two weeks. His team plays Servite at home, a team it beat 42-14 in August. St. John Bosco hosts Orange Lutheran, a team it beat 48-0.

In the City Section, Birmingham will take a 54-game unbeaten streak against City opponents into the Open Division playoffs as the No. 2 seed, but Carson is the No. 1 seed after winning the Marine League and making weekly improvement behind junior quarterback Chris Fields III.

There’s lots of intriguing City Section story lines. Palisades is 10-0 after its campus was shut down because of the Palisades fire, with coach Dylen Smith having to scramble to form a team without a weight room or home field and players losing homes. The team has won a series of close games with a dynamic passing attack featuring quarterback Jack Thomas, who has 42 touchdown passes.

Crenshaw won the Coliseum League title even though its veteran coach, Robert Garrett, has been on administrative leave all season. He has 298 career victories. Interim coach Terrance Whitehead will send his team against San Pedro.

The 11-time City champion Colts will open against King/Drew, which lost to Crenshaw in the Coliseum League title decider but wanted to play in the Open Division. Be careful what you wish for.

Birmingham coach Jim Rose is so busy coaching his team and the school’s flag football team in next week’s Division II playoffs that he’s teaching everyone how to multi-task. Last week, after the flag team won a game, they wanted to stop the bus at Chick-fil-A.

“No, the boys have practice,” Rose said.

It’s been a strange season with more than 40 transfer players declared ineligible for two years for violating CIF rule 202, which bans providing false information to the Southern Section on transfer paperwork. This past week, Norco forfeited six victories when an investigation found a violation of CIF rule 510, which bans undue influence with prior contact before enrolling several players. San Juan Hills forfeited nine games but received an at-large berth to the Division 2 playoffs. Long Beach Poly, which had six players declared ineligible, decided not to enter the playoffs despite finishing second in the Moore League.

Then, on Saturday, JSerra announced it is parting ways with third-year coach Victor Santa Cruz following an 0-5 Trinity League record. JSerra’s season is over after not receiving an at-large berth.

It’s been a season of unusual happenings, so prepare for a postseason of the same.