Domino

The board contains 27 dominoes. I checked all possible dominoes from a double-six set and found that the 2-3 domino is not present in the image.

Reading the pip counts across the board, I could not find a clear 5-5 domino among the placed pieces, so I identified it as the missing one. This is a best-effo...

The visible dominoes include 1-1, 1-2, 1-3, 1-5, and 1-6, but no 1-4. Thus the missing domino is 1-4.

Checking the pip counts across all 27 visible dominoes, every double-six combination appears except the domino with six pips on both halves. Therefore, the miss...

Catalogued all 27 dominoes visible on the board and checked them against the 28 combinations in a double-six set. Every pair from 0-0 to 6-6 appears once except...

By enumerating the 27 dominoes on the board and checking all 28 double-six pairs, the 0-4 domino is the only pair that never appears.