The Cut-Off Isn't a Border: Ranking Your Way Into a School Place

Every admissions round, someone on a parents' group says the catchment is 'about a mile'. Someone else says it's 'definitely 800 metres'. Both are usually wrong, not because they've misread a map, but because they're treating a ranking as a boundary. The last placed distance for a school is not a line drawn around it. It's the distance of the final child admitted after everyone with a higher priority has been sorted. Change the number of siblings in the year, or the number of places, and the cut-off moves. The gate stays put. The inequality doesn't.

A queue, not a fence

In the UK, oversubscribed schools admit by published criteria. The order varies, but a common pattern is: looked-after children first, then siblings, then distance. Distance usually only decides among children in the same priority group. So the 'last placed distance' is not a property of the school. It's a property of that year's applicants. It's the distance of the last child who got in after the sibling places were taken.

That distinction matters because parents often talk as if a school has a catchment radius. It doesn't. It has a rank order. If you live at distance d from the school gate, you're not inside or outside a circle. You're somewhere in a sorted list. The question is whether your d is less than or equal to the distance of the last admitted child—call it D. The rule is simply d ≤ D. The catch is that D is not fixed.

The algebra of the last place

Here's a simplified model. Suppose a school has P places. Suppose S of those go to children with sibling priority. That leaves P − S places for distance-only applicants. Sort those applicants by distance from smallest to largest. The last placed distance D is the distance of the (P − S)th child in that sorted list.

D = distance of the (P − S)th closest distance-only applicant.

You get a place if you have sibling priority, or if your distance d is less than or equal to D. That's it. The algebra is not complicated. The complication is that S changes every year. A sibling-heavy cohort shrinks the number of distance places, which usually pulls D inwards. A quiet sibling year can push D outwards. The same house can be inside one year and outside the next without anyone moving a centimetre.

A worked example from a fictional city

Take a fictional city called Kingsmere. Ravenshaw Academy has 150 places for the 2026 intake. In the simplified model, 30 places go to siblings. That leaves 120 distance places. When the distance-only applicants are sorted, the 120th closest lives 1.36 km from the gate. So D = 1.36 km.

A household at 1.42 km misses out. They decide to move 180 metres closer, to 1.24 km, before the next round. That should be enough, right? Not necessarily. Suppose the next cohort has 46 sibling places. Now only 104 distance places remain. The 104th closest distance-only applicant lives 1.19 km. The household is at 1.24 km—closer than before, but still outside. The move helped their own d. It didn't help enough, because D moved faster.

Now flip it. Another household stays exactly where it is, at 1.30 km. In the first year, with D = 1.36 km, they get a place. In the second year, with D = 1.19 km, the same house misses. No move, no change of address, no change of school gate. Just a different ranking. This is why last placed distances from previous years are useful data but poor promises. They tell you what the queue looked like then. They don't tell you where the cut-off will fall this year.

Straight lines and real streets

There's a second layer: how d is measured. Many UK admissions authorities use straight-line distance from the home address to the school gate, often calculated by a geographic information system. That's Euclidean distance, not walking distance. A house beside a park might be 'closer' as the crow flies than a house on the same road with a more direct pavement route. A railway line can make a short straight line into a long walk. The algebra doesn't care. It just uses the d the authority publishes.

This is where the city gets interesting. The same physical street can produce different d values depending on which gate is used, which entrance is designated, and whether the measurement point is the school building or the boundary. Parents sometimes measure to the front door of the school and get a smaller number than the official one. The official number wins, because that's the d in the inequality.

What the inequality does and doesn't tell you

It tells you that a school place is not a simple postcode lottery. It's a priority order with a distance tie-breaker. It tells you that sibling priority can override distance entirely, which is why a family 3 km away can be admitted ahead of a family 300 metres away if the sibling rule applies. It tells you that the number of places and the sibling count are not background details—they are variables in the result.

It doesn't tell you next year's cut-off. Nobody can, until the applications are in and the criteria have been applied. What you can do is read the admissions booklet carefully. Check the order of criteria. Check how siblings are defined. Check how distance is measured. Look at last placed distances for previous years as history, not prophecy. If you're appealing, the arithmetic is your friend: show the rank, the places, the sibling count, and the measurement method. Don't argue with the circle. Argue with the sorted list.

The school gate looks like a border. It isn't. It's the visible end of a queue, and the queue is an inequality that gets recalculated every year. Once you see D as a variable rather than a wall, the whole catchment conversation makes a lot more sense.