How the Crabtree Index works in Maine high school football
The Crabtree Index is how the Maine Principals' Association (MPA) seeds high school football. It adds a team's own winning percentage to its opponents' combined winning percentage and multiplies by 100. The top 4, 6 or 8 teams by Crabtree Index in each division make the playoffs. Margin of victory and class don't count.
Step 1: your winning percentage
Wins divided by games played. Only completed games count; canceled and postponed games don't.
Step 2: your opponents' winning percentage, pooled
Add up all the wins of every team you played, and divide by all of their games. That's pooled, not an average of each opponent's percentage, and an opponent you play twice counts twice. Out-of-state and non-classified opponents count in your own record but add 0 wins and 0 games to the pool.
Then add the two and multiply by 100
Crabtree Index = (your win % + opponents' pooled win %) × 100
Worked example: Thornton Academy, 2026
Thornton Academy (Class A South) is 9-0 in games through Sat Oct 31.
Win % = 9 ÷ 9 = 1.0000
Its opponents have won 39 of their 80 games combined.
Opponents' win % = 39 ÷ 80 = 0.4875
Crabtree Index = (9/9 + 39/80) × 100 = 148.7500 → 148.750
The MPA shows three decimals and rounds the exact value once. That's the same number on the Thornton Academy page and the standings. The team in this example changes every week.
Three things that surprise people
- Your index can move when you don't play. Your opponents' results count, so their wins and losses change your number every week.
- Beating a strong team helps twice: once in your own record and again through that opponent's wins in your pool.
- A perfect record isn't a perfect index. A team that wins every game against teams that won nothing else scores exactly 100.
How many teams make the playoffs
| Division | Teams | Make the playoffs |
|---|---|---|
| Class A North | 7 teams | top 4 |
| Class A South | 7 teams | top 4 |
| Class B North | 8 teams | top 6 |
| Class B South | 7 teams | top 6 |
| Class C | 12 teams | top 8 |
| Class D North | 7 teams | top 6 |
| Class D South | 7 teams | top 6 |
| 8-Man Large North | 5 teams | top 4 |
| 8-Man Large South | 6 teams | top 4 |
| 8-Man Small North | 5 teams | top 4 |
| 8-Man Small South | 7 teams | top 4 |
Qualifier counts as labeled by the MPA.
Who wins a tie
When teams have exactly the same Crabtree Index, the MPA goes in this order: head-to-head, then division record, then overall record, then Heal points. If they're still tied after all four, the MPA settles it.
Quick answers
What are Crabtree points?
Crabtree points are a team's Crabtree Index, the number the Maine Principals' Association (MPA) uses to seed high school football: the team's winning percentage plus its opponents' combined winning percentage, times 100. A higher number means a better seed. Margin of victory and class don't count.
How many teams make the Maine football playoffs per class?
It depends on the division, as labeled by the MPA: the top 8 in Class C; the top 6 in Class B North, Class B South, Class D North and Class D South; the top 4 in Class A North, Class A South, 8-Man Large North, 8-Man Large South, 8-Man Small North and 8-Man Small South. Teams are ranked by Crabtree Index within their division.
Who wins a tie in the Crabtree Index?
When two or more teams have exactly the same Crabtree Index, the MPA breaks the tie in this order: head-to-head, then division record, then overall record, then Heal points. A tie still left after all four is settled by the MPA.
Is the Crabtree Index the same as Heal points?
No. Football is seeded by the Crabtree Index; Heal points are only its fourth tiebreaker. Maine high school basketball and most other sports are seeded by Heal points.
Crabtree standings, every division · Playoff picture · Playoff bracket · How Heal points work (basketball)
Source: the MPA football bulletin and Crabtree method. Official standings are the MPA's; we recompute them from public results and check against the MPA's table every week.