Which of these "Square One" contexts are you most interested in exploring further? Statistics at Square One - The BMJ

Statistics at Square One is a classic introductory text published by The BMJ that breaks down complex data concepts into manageable "first principles". 5. Tactical "Square" Texts

The most common theory points to early BBC radio broadcasts. Commentators used a numbered grid in newspapers to help listeners visualize the field; "Square One" was the area around the goal.