Analysis of information sources in references of the Wikipedia article "Scrabble" in English language version.
Scrabble transitioned from living-room novelty—nearly 4 million sets were sold in 1954—to competitive passion in the 1960s, when it landed alongside chess, backgammon, and bridge in smoke-filled games parlors in New York City. ... When the tiles were placed in bags during games, unscrupulous players could feel around for the blanks because they had no grooves, a tactic known as "brailling".