A strange little side quest
Between one round of Army Block Squad and the next, this is worth knowing: Arthur Wynne published a diamond-shaped 'Word-Cross' in the New York World on December 21, 1913; the name later shifted to 'Cross-Word' and then 'crossword'. There is another connection worth keeping in the same mental pocket: Games resembling checkers were being played thousands of years ago; evidence of related games reaches back to around 1600 BC. That long chain of experiments is part of why puzzles still feels fresh when a game finds the right twist.
