Ah, it took me a while to think it through, but I get it now. The table of double digits is square, but because there’s no 0 character included in the 26 letters of the alphabet, the single digit set adds an extra row to the start.

But that’s the reason there are 27 in the first set and 26 in every set after that. If you start from 1, it’s 26 in every set, as you would expect, right?

Is it reasonable to say the game has been “made”?

Maybe there’s something I don’t get here, but the rows are counted in base 10 starting from 1. Why would you start numbering columns from 0?