Data & Games

Why some people mow a lawn better than others

By Russell Samora, Florina Sutanto, Arjun Kakkar, and Sushant Karki

A gardener pushing a push-reel lawn mower across a lawn, posed in 1917 to illustrate Rudyard Kipling's poem "The Glory of the Garden" — Credit: Frances Benjamin Johnston / Library of Congress, 1917 — no known copyright restrictions

Mowing a lawn or vacuuming a rug is second nature for most of us — some part of the brain works out a decent route without much conscious thought, and it turns out people are surprisingly good at it, better than you'd expect for a problem that gives computers real trouble. To put that instinct to the test, The Pudding built a small interactive lawn and asked readers to mow it, quietly logging every path along the way.

The full piece pulls from more than 132,000 of those recorded attempts. It's a hands-on way into a genuine computer-science puzzle called coverage path planning, a close cousin of the famous Traveling Salesman Problem — the kind of route-finding a delivery driver or a trick-or-treater solves without ever naming it.

Interactive

Give it a try — how efficiently can you mow this lawn?

Click and drag across the grass. It's a small lawn: just 49 squares.

On this same small lawn, nearly 31,000 real readers mowed the identical 49 squares. More than half landed within five moves of the shortest possible route, and roughly one in six found a perfect path outright — a lot of different routes converging on similarly good outcomes. The full article walks through one of those runs move by move, showing exactly where people pause, where paths diverge, and why the shortcuts everyone falls back on tend to work about as well as they do.