Chimp test

How a run works

The first board scatters the numbers 1 through 4 across the arena. Nothing is timed while you study it: the digits stay visible for as long as you like, and the board only locks when you tap 1. At that moment every remaining square goes blank. The squares themselves stay on screen, so you can see where the numbers are, you just can no longer see which is which. Tap them in ascending order from memory. Clear the board and the next one has one more number.

Mistakes are strikes, and you get three for the entire run, not three per board. A wrong tap replays a board of the same size with a completely new layout, so a strike costs you a fresh memorization rather than a chance to fix the old one. The third strike ends the run, and your score is the largest board you completed. Boards below the starting size do not count, so a run that dies on the first board scores zero.

Strategy, from someone who has lost many strikes

Because study time is unlimited, the game is really about how well you encode before touching 1, and most people tap 1 far too early. Build a route first: find 2, 3, 4 and rehearse the path between them as a sweep of the hand, then place the higher numbers along it. A path is one thing to remember; eight independent locations are eight things.

The tip that separates decent runs from good ones concerns where you spend your care. After the board locks, the blank squares confirm every position, so your errors will almost never be "I forgot where a square was." They will be order swaps between two mid-sequence numbers that sat near each other. When two digits are adjacent on screen but not in sequence, say 5 and 8 side by side, give that pair its own explicit rehearsal before you start. Those pairs are where nearly all strikes happen. And once you are moving, keep moving: recall decays across the seconds it takes to clear a big board, so a brisk confident pace through the numbers you are sure of leaves your remaining memory for the last two or three.

Context for your score

Most people complete boards of 7 to 9 numbers. The test is modeled on a Kyoto University study in which a chimpanzee named Ayumu recalled nine-digit layouts after seeing them for a fraction of a second, faster and more reliably than the university students tested against him. You get unlimited study time and it is still hard, which is the enduring point of the exercise.

Design notes

Layouts are random each board, with placement logic that keeps squares from overlapping, and a replayed board after a strike is always a new layout. The blank squares remaining visible is a deliberate softening compared to the original study; you are recalling a position-to-digit mapping, not raw positions in empty space. Taps register on pointer contact. Your best board size is stored in your browser only, and there is no leaderboard or server-side anything. The game also never accelerates or adds a timer as boards grow: difficulty comes entirely from one more number than last time, which turns out to be plenty.