AFL margin betting is a bet on a team to win by a set range of points rather than simply to win. Bookmakers commonly split each team's win at 40 points, 1 to 39 or 40 or more, and sell the four outcomes as big win little win. Narrower bands, such as 1 to 9 or 10 to 19, pay longer prices for a tighter range.
Counted from the AFL's published results for the 2022 to 2026 home-and-away seasons, 686 of 1,026 games (66.9%) were won by 1 to 39 points, 330 (32.2%) by 40 or more, and 10 (0.97%) were drawn. Those are base rates across every kind of game. In a single game the line decides how the chances split, which is why margin prices start from the AFL line.
How AFL margin bands settle
A band includes both ends: 1-39 covers every win from 1 point to 39 points, and a 40-point win belongs to 40+. Each band belongs to one team, so a big win little win market lists four selections, two per team, and some lists add the draw.
Settlement uses the final margin. Scores are goals, behinds and total, with a goal worth 6 points and a behind 1 in the AFL's stats glossary:
| Final score, Team A first | Margin | Band that wins |
|---|---|---|
| 14.10 (94) to 8.7 (55) | Team A by 39 | Team A 1-39 (little win) |
| 14.11 (95) to 8.7 (55) | Team A by 40 | Team A 40+ (big win) |
| 9.9 (63) to 10.4 (64) | Team B by 1 | Team B 1-39 (little win) |
| 8.8 (56) to 8.8 (56) | Draw | None of the four; see the draw section |
The first two rows differ by one behind, and that behind moves the bet from one band to the other. Narrow bands have a boundary like that at every step: a 19-point win is in 10 to 19, and a 20-point win is in 20 to 29.
Here is how often each range came up across the 1,026 games, counting either team as the winner:
| Winning margin | Games | Share of games |
|---|---|---|
| 1 to 9 | 213 | 20.8% |
| 10 to 19 | 195 | 19.0% |
| 20 to 29 | 153 | 14.9% |
| 30 to 39 | 125 | 12.2% |
| 40 to 49 | 91 | 8.9% |
| 50 to 59 | 80 | 7.8% |
| 60 or more | 159 | 15.5% |
| Draw | 10 | 1.0% |
The share won by 40 or more ranged from 29.8% (2022) to 34.3% (2025 and 2026). Close games are the most common single range, and the open-ended top band collects a long tail of blowouts.
Big win little win: four outcomes from one game
Big win little win turns one game into four bets: Team A by 1 to 39, Team A by 40 or more, Team B by 1 to 39, Team B by 40 or more. The draw is a fifth result whether or not it is listed.
With a main line of -15.5 on the favourite, an illustrative model (worked in the next section) gives these chances. The illustrative prices shade each fair price, and the last column is what each bet returns per $1 if the model's chances are right: chance x price.
| Outcome | Model chance | Fair price | Illustrative price | Return per $1 at fair chance |
|---|---|---|---|---|
| Favourite by 1 to 39 | 40.90% | $2.44 | $2.30 | 94c |
| Favourite by 40+ | 25.25% | $3.96 | $3.60 | 91c |
| Underdog by 1 to 39 | 26.51% | $3.77 | $3.45 | 91c |
| Underdog by 40+ | 6.33% | $15.80 | $13.00 | 82c |
| Draw, where listed | 1.01% | $99.01 | $67.00 | 68c |
Two things stand out. The favourite's little win is the most likely single outcome, even though the line says the favourite should win by about 15 or 16. And the five prices add up to a book of 109.4%: 1 / 2.30 + 1 / 3.60 + 1 / 3.45 + 1 / 13.00 + 1 / 67.00 = 1.094. A line priced at $1.90 on both sides is 105.3%.
Example: Illustrative prices and an illustrative model, not a real game or a current market. Favourite by 1 to 39: 0.409 x 2.30 = 0.94, so the bet returns about 94c per $1 if the model is right.
Pricing margin bands from the line
The line is the market's middle: at -15.5 with both sides near even money, the favourite is about a 50% chance to win by 16 or more. Margin bands are slices of the same picture, so you can price them from the line in four steps.
- Take the line as the centre of the likely margins.
- Choose a spread: how widely results scatter around that centre, measured as a standard deviation. The model uses an illustrative 36 points, the assumption behind the AFL line guide's alternate lines. All final margins in 2022 to 2026 scattered more widely, at about 41 points, because they mix every kind of game, while one game's line has already priced the gap between the teams.
- Read off the chance of each band from a normal curve with that centre and spread. The favourite by 1 to 39, for example, is the chance the margin lands between 0.5 and 39.5 points: 40.9%.
- Fair price = 1 / chance, then compare it with the bookmaker's price.
You can also run it backwards to check a bookmaker's bands against its own line. Strip the margin out of the big win little win prices above by dividing each implied chance by the book: the favourite's two bands come to 39.7% + 25.4% = 65.1%. In the model, the favourite's 1 to 15 point wins hold about 16.2%, which leaves about 48.9% for a win by 16 or more. That is close to the 50% a -15.5 line implies, so the two markets agree.
The step that matters most is the spread, and the line does not pin it down. Holding the line at -15.5:
| Assumed spread | Favourite by 10 to 19, fair price | Favourite by 40+, fair price | Underdog by 40+, fair price |
|---|---|---|---|
| 32 points | $8.06 | $4.41 | $23.35 |
| 36 points | $9.06 | $3.96 | $15.80 |
| 40 points | $10.06 | $3.65 | $11.83 |
The line is a 50% chance in all three rows, yet the underdog's big win runs from $11.83 to $23.35. That uncertainty is one of the reasons margin markets are priced with more room than the line.
Risk: Betting involves risk. A model is an estimate, and a band priced above a model's fair price can still lose, and often does. See responsible gambling for limits and support.
Draws in margin markets
Draws are rare but real: 10 of the 1,026 home-and-away games from 2022 to 2026, between one and three a season. A home-and-away game can end level; a final cannot.
When the draw is listed in a margin market, it is a selection like any other, usually at a long price. When it is not listed, the bookmaker's terms decide what happens to the bands, and the rule types differ: every band can lose because none of them came in, stakes can be refunded, or another rule can apply. Find the clause before you bet, because a draw is roughly a 1 in 100 result.
In a final, Regulation 2.8 of the AFL Regulations sends a tied game to extra time. On the score at the end of normal time that game is a draw, which none of the four big win little win selections covers; on the score after extra time it is a win for one side. Your terms say which score counts, and a stopped home-and-away game has its own AFL rule, so AFL draw rules sets out how each case settles.
Why narrow bands carry more margin
The book percentage, the sum of 1 / price across every outcome, is the quickest measure of what a market costs. Here is a ten-point band market on the same game, priced from the same model (fair prices) with illustrative bookmaker prices:
| Winning margin | Favourite fair | Favourite price | Underdog fair | Underdog price |
|---|---|---|---|---|
| 1 to 9 | $10.49 | $9.00 | $11.81 | $9.50 |
| 10 to 19 | $9.06 | $7.50 | $12.78 | $10.00 |
| 20 to 29 | $9.34 | $8.00 | $16.72 | $13.00 |
| 30 to 39 | $10.40 | $8.50 | $23.60 | $17.00 |
| 40 to 49 | $12.50 | $10.00 | $35.98 | $26.00 |
| 50 or more | $5.80 | $4.80 | $28.17 | $21.00 |
With the draw at $67.00, the thirteen prices add up to a book of 123.7%. Set beside the other two markets:
| Market on the same game | Outcomes | Illustrative book | Return per $1 at fair chances |
|---|---|---|---|
| Line, -15.5 at $1.90 a side | 2 | 105.3% | 95c on each side |
| Big win little win, draw listed | 5 | 109.4% | 68c to 94c |
| Ten-point bands, both teams, draw | 13 | 123.7% | 68c to 86c |
Several things push a narrow-band market's book up:
- The spread is harder to price than the middle, as the spread table in the worked example shows, so a bookmaker builds in room against being wrong about the shape.
- Every band is a long price, and in this table each band is shaded harder than the line: $10.49 shaded to $9.00 gives up 14%, while $2.00 shaded to $1.90 gives up 5%.
- Where fewer bookmakers post a market and fewer punters compare it, there is less pressure to keep each price close to fair.
None of that is fixed. Check the market you are betting by adding up 1 / price for every band, both teams and the draw, and compare it with the line on the same game. Bookmaker margin explains the book percentage, and the bookmaker margin calculator does the sum.
Mistakes in AFL margin betting
- Reading 1 to 39 as a comfortable win. It is the close-win band and includes every 1-point win.
- Using season base rates as one game's chances. The 32.2% for 40 or more is an average over every kind of game; in a game with a big line, the favourite alone can be close to an even chance to win by 40.
- Forgetting the draw. If it is not listed, read the terms before you assume a refund.
- Judging a band by its price alone. $9.00 for a ten-point band can sit well below a fair $10.49, and the book percentage is what shows it.
- Ignoring the boundary. One behind moves a 39-point win to 40, so a game expected to finish near a band's edge is close to a coin toss between the two neighbouring bands.
Margin bands or the line?
Margin bands sit beside the head to head, line and totals in the AFL betting market map. The line asks one question at a small book, about 105% in the examples here, and a margin band asks a sharper question at a bigger book.
Back a band only when your view is about the shape of the result, for example that a game is more likely to be a blowout than the line suggests. Even then, the band's price has to sit above the fair price your own estimate gives it. If the same view can be put on an alternate line, compare the two prices first.
The B337 Terminal shows prices from 40+ bookmakers across racing and sports, and on its sports board AFL head to head, line and total prices sit in one column per bookmaker. The line you price the bands from can be read across bookmakers, with flucs showing how it has moved. Not every bookmaker prices every game. The board is read on a repeating cycle, not tick by tick, so check the price in your own account before betting. A free account opens a limited view of the Terminal with live odds.
Risk: Betting involves risk. A sharper question pays more when it lands and loses more often, and there is no guarantee of profit. See responsible gambling for limits and support.