Your winning percentage, plus your opponents’ collective winning percentage, times 10.

That’s the relatively simple Crabtree point formula used to rank Maine high school football teams for postseason play. We all know from experience, of course, that Week 8 results can change that picture dramatically.

Here’s a quick primer on how things should shake out after Friday and Saturday’s results:

Class A North

Assuming a crossover win at home over rival South Portland (2-5), Portland (7-0) will finish No. 1 by a comfortable margin. The second quarterfinal bye will go to the winner of Cheverus (5-2) at Windham (5-2).

Six teams makes the cut. Lewiston (2-5) at Edward Little (2-5) is essentially a playoff for the No. 4 seed and the right to stay home next week. Bangor (1-6) at Oxford Hills/Buckfield (1-6) is an elimination game. If the Blue Devils lose to the Red Eddies, the Rams-Vikings winner likely vaults to No. 5, with strength of schedule giving that team the edge.

Class B

Falmouth (7-0) has sewn up the No. 1 seed in the South and home field advantage throughout the playoffs. Leavitt has the inside track to the No. 2 seed, but the Hornets (5-2) need to win at Biddeford (5-2) and have the favored team win all other games to solidify their strength of schedule.

Leavitt and Marshwood (5-2) played six common opponents, so those cancel out in the Crabtree calculations. The Hornets also played Morse (2-5) and Spruce Mountain (3-4), while the Hawks faced Kennebunk (5-2) and Gorham (0-7). Leavitt needs its two unique opponents to finish with more combined wins than Marshwood’s, To gain the edge, the Hornets are rooting for Morse to handle Mt. Ararat (1-6) and Spruce to stop Mountain Valley (2-5).

Brunswick is poised to claim the top seed in the North with a win over Nokomis. In the event of a three-way tie involving Brewer and Skowhegan at 7-1, the Indians likely will edge the Witches for the No. 2 seed based on strength of schedule. Barring a win at Skowhegan and some outside help, Mt. Blue would be No. 4 and host Cony next week.

Class C South

Yarmouth (7-0) is locked into the No. 1 spot. Unless upsets prevail elsewhere, Cape Elizabeth (6-1) seems safely slotted second no matter what happens Friday in its game against No. 3 Wells.

Fryeburg (4-3) and Spruce Mountain (3-4) are on a collision course to meet in the 4-vs.-5 quarterfinal next week. The Phoenix’s strength of schedule makes that a close race despite the Raiders having an extra win. Poland (3-4) at Gray-New Gloucester (4-3) will settle the No. 6 and 7 positions. Mountain Valley is unlikely to nudge higher than No. 8 unless the Falcons upset Spruce Mountain.

Class D South

No. 1 Oak Hill, No. 2 Winthrop and No. 4 Lisbon are heavy favorites this week, so the swing game is No. 3 Dirigo (5-2) at No. 5 Maranacook (4-2). The Cougars would stay third and secure a home quarterfinal game against Old Orchard Beach with a win. They would fall beneath the Black Bears and return to Readfield next week if they lose.

Lisbon will be third or fourth, depending on the result of that game, and host either Maranacook or OOB. Oak Hill will be home against Boothbay, with Winthrop/Maranacook entertaining Traip.