A hundred stopovers takes you three times around the Earth

CouchColumbus lets you pick anywhere from 0 to 100 stopovers. You can guess that the line on the map gets longer as the number climbs, but not by how much. So we measured it.

Seoul to Paris

The direct distance is 8,966km. We generated 300 itineraries at each setting and averaged them. Which cities get drawn changes every time, so measuring once would mean nothing.

Stopovers	Average total	vs. direct
0	8,966km	1.00×
1	10,257km	1.14×
3	12,589km	1.40×
6	16,131km	1.80×
12	23,400km	2.61×
25	37,972km	4.24×
50	66,801km	7.45×
100	125,819km	14.03×

At the default of three stopovers: 12,589km, or 1.4× the direct route. Roughly 1,200km added per stop, about the same as a return trip from Seoul to Tokyo.

Put in a hundred and you get 125,819km. The Earth's circumference is 40,030km, so that is a little over three times around the planet. To visit Paris once.

New York is worse

Run the same calculation on Seoul–New York and it looks like this.

Stopovers	Average total	vs. direct
0	11,053km	1.00×
3	18,303km	1.66×
12	36,049km	3.26×
100	195,493km	17.69×

The direct route is longer and the multiplier is bigger too. At a hundred stopovers it reaches 17.69×, or 195,493km — four and a half times around the Earth.

The reason is the density of cities lying on the way. The great circle from Seoul to Paris cuts across Siberia and drives through the Eurasian landmass. Cities are packed underneath it, so slotting one in barely pulls you off course. The Seoul–New York route, by contrast, crosses the Pacific and the Arctic. There is almost nothing under it, so filling in stopovers means dragging in cities far off the line.

Why it does not add 1,200km a time, but steepens

Every individual stopover respects the rule "detour ratio within 1.4" — going by way of that city does not exceed 1.4× the direct route. But that rule looks at one city at a time.

Each of them may sit on the way, and yet stringing them together in order tells a different story. A little north of Seoul, then a little south, then north again: a zigzag. Individually every leg is "on the way"; connected, the whole thing is a sawtooth. The more stopovers, the finer the teeth, and so the multiplier grows steeply rather than linearly.

The playback gets longer too

More distance means more to watch. Back when total playback was fixed at 18 seconds, twelve stopovers meant 1.4 seconds a leg — gone before you could read the city name. Now it scales with the number of legs, capped at 75 seconds. A hundred-stopover journey runs 75 seconds, or 4.7 seconds at 16× speed.

So how many is right

Practically, three to six. That lands at 1.4–1.8× the direct route: enough to feel like you took the long way, still within the bounds of a believable itinerary.

A hundred is less a feature than a joke. You end up with 102 stops, one to three nights in each, and an itinerary running about 300 days. Three times around the Earth, drifting for ten months. Just as well you did not go.