Field position: the value of a turnover

Where you win the ball back decides how much it's worth. Win it in your forward 50 and you score more than half the time. Win it in defence and it's almost nothing.

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Every turnover feels like a win in the moment — you've got the ball back. But a turnover isn't a turnover. Win the ball back on your own goal line and you've got a long way to go and a packed ground to navigate. Win it 40 metres from goal and you're half a kick from a score.

We measured exactly how much that difference is worth. For every intercept in our captured AFL data, we tracked where on the ground it happened and whether the chain it started ended in a score.

The closer to goal, the more it's worth — steeply

An intercept won deep in your own defensive 50 turns into a score about 10% of the time. Win it in the midfield and that doubles to 21%. Win it inside your forward 50 and it becomes a score 57% of the time — not substantially better than a coin flip, but a coin flip that lands your way.

That's a near six-fold swing from one end of the ground to the other. The same act — winning the ball back — is worth roughly six times as much in attack as in defence. (Coaches will recognise these numbers: they line up almost exactly with the old rule of thumb that intercepts convert at roughly 10% in defence, 20% through the middle, and 60%-ish inside 50. The data backs the folklore.)

There's a volume story sitting alongside the conversion story. Midfield is where roughly six in every ten intercepts happen, so even at 21% conversion it produces the bulk of your scoring from turnovers — the largest filled area in the chart above. Forward-50 chances are the opposite: rare (about one in fifteen), but they convert at a near coin-flip rate. The midfield is the engine; the forward 50 is the leverage.

Two sides of the same lever

This cuts both ways, and the defensive side is the one teams underrate.

If a forward-50 turnover is worth 57% to the team that wins it, then your turnover deep in your own defensive 50 hands the opposition a coin-flip score. A sloppy kick across your own back line isn't a 10% mistake — from the opposition's point of view, it's a 57% gift, because their intercept is in their forward 50. The most expensive ball you can lose is the ball in your own defensive half.

So the same number drives two of the highest-leverage habits in football: hunting the ball in your forward 50, and protecting it like gold in your defensive one.

What this means for your team

• Forward-50 pressure is your most valuable defensive act. A tackle, smother or chase-down that wins the ball back inside attacking 50 is worth nearly six ordinary turnovers. The forwards who lock the ball in and hunt it down are doing premium defensive work, not garbage time.
• Your defensive-half ball use is non-negotiable. A turnover in your own back half gives the opposition the most valuable turnover there is. "Take the safe option out of defence" isn't conservatism — it's denying a 57% chance.
• Rate your turnovers by where they happen, not just how many. Ten turnovers in the opposition's defensive 50 are cheap. Three in your own back half can lose you the game. Win/loss reviews should weight the location, not just the count.
• It reframes the forward press. Pushing numbers up to win the ball high isn't only about territory — every turnover you force up there is a near-even-money score.

In short

• An intercept's value rises steeply toward goal: ~10% to score in your defensive 50, ~21% in the midfield, 57% in your forward 50 — a near six-fold swing.
• Winning the ball back in attack is the highest-value turnover in football, which makes forward-50 pressure premium defence.
• Losing the ball in your own defensive half is the most expensive mistake — it hands the opposition that same 57% chance from the other side.

The fact that the zone a turnover happens in changes its value by a factor of six is the by-source pattern in microcosm — see the series' closing piece for the wider rule: Correlation is not causation.

A note on the data

This pools every intercept (a possession won back from the opposition in open play) across captured local-league AFL games, after filtering out demo data, unfinished matches and drawn quarters. Each intercept is bucketed by field zone at the moment it was won, and we record whether the resulting chain ended in a goal or behind. "Conversion" is the share of intercepts in each zone that produced a score.