Expected value model

The probability a pass from to will be marked by .

22.8%

30° Left30° Right50m40m30m15mCollapse recommended play badgeAaron NaughtonA NAUGHTONRECOMMENDED PLAYTake the ShotPass mark rate: 23%. Using AFL average 2026 M50 rate.Pass mark rate: 23%. Using AFL average 2026 M50 rate.23%
Aaron Naughton

Career Games

176

Career Shots

575

Zone Accuracy

40%

Career Goals

312

Accuracy40%
Western Bulldogs

Career Games

115

Career Shots

1,895

Zone Accuracy

89%

Career Goals

1,034

Accuracy89%

Decision thresholds

22%

Direct Shot Accuracy Need

If Aaron Naughton is a 22% goal kicker or better from this map spot, the recommended play would be to take the shot.

43%

Mark rate needed

If the pass from Aaron Naughton to Western Bulldogs can be marked at a rate higher than 43%, the recommended play would be to pass the shot.

No Path

Second Shot Accuracy Needed

Even if Western Bulldogs is a 100% goal kicker. The current mark rate (23%) is too low or Aaron Naughton accuracy (40%) is too high to recommend a pass.

Model Controls

Model Toolkit

Pass Mark Distance Modifiers

On
Distance
Modifier
25% base
0-5m
1.20x
30.0%
0-10m
1.10x
27.5%
0-25m
1.00x
25.0%
0-30m
0.95x
23.8%
0-40m
0.85x
21.3%
0-55m
0.70x
17.5%
0-70m
0.60x
15.0%
0-85m
0.40x
10.0%

Pass mark rate uses the slider as the final rate at the current distance between and . Moving either marker then scales that hidden base rate by the distance modifier, with values interpolated between rows.

These pass-distance modifiers are author assumptions for modelling only, not observed pass-mark data.

Turning this off keeps the pass mark slider independent from the distance between the two map markers.

Player Data Set Table

Expected Value Results

EV Values of different parts used in the model.

Possession Outcome

Take the shot

Using the current and marker locations plus the adjustment sliders above, taking the original set shot has the higher expected value. Under these assumptions, choosing the shot over similar possessions is expected to produce more points per possession than passing.

Toolkit

Tools, datasets, and model references for exploring set-shot decisions.

EV Variance CalculatorCompare shot and pass edge, noise, and sample-size stability.Set Shot AnalyticsDetailed set-shot data tables and charting workspace.

AFL Set Shot Guide

A brief guide to set shots, expected value, and reading the model.

What is an AFL set shot?

An AFL set shot is a kick at goal taken after a mark or free kick. The player has time to set up, so distance and angle become major parts of the decision. A central 45-metre shot can be very different from a wide 45-metre shot, even if both are recorded as the same distance from goal.

What does expected value mean?

Expected value estimates the average points a choice is worth over many similar possessions. A shot worth 2.4 expected points is not predicted to score exactly 2.4 points once. It means across similar possessions, every time you take the shot, on average you will earn 2.4 points per possession. So across similar 100 possessions, you'd expect to earn 240 points from taking the shot

Why compare shot and pass?

Long set shots are often passed off because a teammate may get a closer kick. The pass has to be marked first, though. If the mark is unlikely, the original kicker may only need to be a modest goal chance for taking the shot to be the better possession.

How pass mark rate works

Pass mark rate is the chance the ball is successfully marked by the teammate at the second-shot location. For example, a 25% pass mark rate means 25 of 100 pass attempts are marked before the teammate can take the next set shot.

How behinds change the model

Behind rates matter because a missed goal can still score one point. A low-accuracy long shot can still have useful expected value if many of the misses score behinds, while a failed pass may produce no immediate score.

How to read the decision

The recommended play is the higher expected-value option under the current map locations and model controls. If the set-shot EV is higher, the model favours taking the shot. If the pass option EV is higher, it favours passing.

Model Formulas

Formulas for comparing set-shot EV, pass EV, mark rate, behinds, optional unmarked-pass scoring, and play-on scoring.

Simple set shot EV

EV = Accuracy x 6 + (1 - Accuracy) x 1

The basic expected value of a set shot. A goal is worth 6 points. This simple version assumes every missed goal still scores a behind worth 1 point.

Behind-rate adjusted EV

EV = Accuracy x 6 + (1 - Accuracy) x behindRate

The adjusted version used by the sliders. The behind rate is applied only to shots that miss the goal. For example, a 50% accurate shot with a 65% behind rate gives 50 goals plus about 33 behinds from the 50 missed goals.

O set shot EV

EVO = accO x 6 + (1 - accO) x behindRateO

The expected value of taking the original shot from where the mark or free kick was paid: goals first, then behinds from the share of missed goals that still score.

X set shot EV

EVX = accX x 6 + (1 - accX) x behindRateX

The value of the shot after a successful pass is marked: goals first, then behinds from the share of missed goals that still score. This is calculated before applying the chance that the pass is actually marked.

Pass-to-mark rate

passToMarkRate = 1 - playOnRate

This is the share of pass-option possessions that still become pass-to-mark contests after the play-on branch is applied. If the Play-On Rate toggle is off, playOnRate is 0 and passToMarkRate is 1.

Mark-contest EV

MarkContestEV = (markRate x EVX) + ((1 - markRate) x unmarkedShotRate x unmarkedAverageScore)

This is the value of the pass-to-mark branch before the play-on rate is applied. Successful marks use the X set-shot EV. Unmarked passes use unmarkedShotRate for how often a loose pass still generates a shot chain, then unmarkedAverageScore for that chain's expected points.

Play-on EV

PlayOnEV = playOnAverageScore

This is the value of pass-option possessions that turn into play-on instead of pass-to-mark contests. If the Play-On Rate toggle is off, this branch contributes 0 to the pass option.

Pass option EV

PassEV = passToMarkRate x MarkContestEV + playOnRate x PlayOnEV

The full pass option EV combines the pass-to-mark branch with the play-on branch. If the Play-On Rate toggle is off, passToMarkRate is 1 and the model reduces to the mark-contest branch.

Full pass option EV

PassEV = (1 - playOnRate) x [(markRate x EVX) + ((1 - markRate) x unmarkedShotRate x unmarkedAverageScore)] + playOnRate x playOnAverageScore

This is the pass option written out in full. The first term values the pass-to-mark contests using successful marks plus optional unmarked-pass scoring. The second term adds average points from play-on possessions when Play-On Rate is turned on.

Shot edge

ShotEdge = EVO - PassEV

Shot edge is the O set-shot EV minus the pass option EV. Positive means the shot is ahead. Negative means the pass is ahead.

Unmarked shot EV

UnmarkedEV = unmarkedShotRate x unmarkedAverageScore

This only applies after a pass-to-mark contest is not marked. In MarkContestEV, the marked branch is markRate x EVX, while the unmarked branch is (1 - markRate) x UnmarkedEV. If this toggle is off, UnmarkedEV contributes 0.

Mark rate needed

markRateNeeded = (EVO - playOnRate x playOnAverageScore - passToMarkRate x UnmarkedEV) / (passToMarkRate x (EVX - UnmarkedEV))

This is the break-even mark rate needed for passing to match shooting after accounting for the play-on branch and optional unmarked-pass scoring. If Play-On Rate and Unmarked Shot Rate are both off, this simplifies to EVO / EVX.

Goal accuracy needed

accO = (PassEV - behindRateO) / (6 - behindRateO)

The direct goal accuracy needed tells you how accurate the original shot must be for shooting to equal the current pass option under the active mark-rate, behind-rate, and pass-leading-to-score assumptions.

Full decision EV

DecisionEV = OShotEV - PassEV
Full formula
DecisionEV = [accO x 6 + (1 - accO) x behindRateO] - {(1 - playOnRate) x [markRate x [accX x 6 + (1 - accX) x behindRateX]+ (1 - markRate) x [unmarkedShotRate x unmarkedAverageScore]] + playOnRate x playOnAverageScore}

This is the complete decision comparison. The O shot side includes the original goal accuracy and original behind rate. The pass side includes play-on scoring, pass-to-mark contests, the X shot goal accuracy and behind rate after the mark, plus optional average-score value from unmarked passes. A positive DecisionEV favours taking the shot; a negative DecisionEV favours passing.