Why the longest path wins the race.

Added: 2026-05-27

[00:00:00]In the 2017 All Japan Micromouse competition, both the bronze and silver placing mice found the shortest path to the goal. And once they did, they were able to zip along it as quick as 7.4 seconds.

[00:00:13]But Masakazu Utsunomiya's winning mouse, Red Comet, did something entirely different. This is the shortest path to the goal, the one that everyone took.

[00:00:23]This is the path that Red Comet took.

[00:00:26]It's a full 5 and 1/2 m longer. That's because micromice aren't actually searching for the shortest path, they're searching for the fastest path. And Red Comet's search algorithm figured out that this path had fewer turns to slow it down. So, even though the path was longer, it could end up being faster.

[00:00:44]So, it took that risk.

[00:00:50]It won by 131 milliseconds.

[00:00:56]Differing routes at competition are now more common than not.