Tiddlywinks. A squop-up is when all one of one set of winks are squopped.
Tiddlywinks can be traced back to the 19th century, but the modern game began with group of Cambridge University undergraduates meeting in Christ’s College in 1955 who wished to devise a sport at which they could represent the university. Within three years, Oxford had taken up the challenge, and from there the game grew with 37 universities competing in the 60s.