What if 9=9 was the only equation in the Maths dictionary? How long could it stretch in a custom size of Scrabble board? I played it by myself for 2 players in a 15×15 board as I did not want the computer players to botch the ends with a dead end as by the dictionary stretching in all directions would essentially yield the same scores if there were no premium squares.

1 point: = ×50
2 points: x ×50

I was inspired on this dictionary by 8=8 equation extending 3 times in the end game when I was playing a game of Maths Scrabble. Here I replaced 8 or 9 with 'x', to be not specific about the digit used. I played it with 10 tiles in each of player's racks but it can be lower, so as to maintain at least one 'x' tile and one '=' tile in the rack always. Otherwise player has to lose a turn by swapping tiles. x=x is the only word in the Zigzag dictionary. Even if a player has multiple 'x' and multiple '=' in the rack, longer words containing multiple 'x' and multiple '=' are not allowed in a single turn.