How to play
Roundtrip
Eight cities, one leg you may not fly. The obvious loop wants that leg.
- Eight cities appear on the map, with one leg between two of them crossed out.
- Put them in the order you would visit them, returning to where you started. You may not fly the crossed-out leg in either direction, and that includes the last hop home.
- Submit the loop.
How it is scored
Your route is measured against the true shortest loop that obeys the closed leg, which we compute exactly by checking all 1,800 legal loops. The score is your distance as a percentage of that optimum, so 100% is perfect and there is no partial credit for a route that looks tidy. Getting within a few percent by eye is a real result.
The closed leg is the whole difficulty. Without it, tracing the outline of the cities and threading the inner ones into the nearest edge finds the perfect loop on almost every map, because the shortest loop never crosses itself and can simply be seen. One shut leg breaks that. The board will not let you fly it either: tap a city that would take you along it and it says so, and the hop home counts the same way, so it stops you before you can strand yourself one city short.
How to get better at it
Think in loops, not legs. Visiting the nearest city next feels efficient and is the trap the maps are built around: greedy ordering is usually beaten by several percent.
If your route crosses itself, you can do better. Uncrossing two legs never makes a loop longer, so a crossing is a free improvement you can see with your eyes. That is also why the closed leg matters: the tidy loop your eye finds first is often the one that flies it, and then the fix is not something you can see.
So work out the best loop, notice whether it uses the closed leg, and if it does, look for the cheapest way to break it rather than starting again. Usually you reverse one run of cities, which keeps everything else where it was. Occasionally the whole shape has to change, and those are the maps where a few percent is a good day.
Find the outlier first. Most maps have one city well away from the cluster, and the question is never whether to visit it but where in the loop it belongs. Tacking it on at the end is almost always worse than threading it through.
Getting within a few percent by eye is a genuinely good result. Hitting exactly 100% usually means you found the one ordering that threads the outlier correctly and stayed off the closed leg while doing it.
When it resets
New puzzle at your local midnight.