Tiddlywinks.

Games H2G2 has a suitably impressive, if slightly ancient (1999, updated 2008) entry on Tiddlywinks:

"Like so many sports and games, tiddlywinks was transformed from child's play to competition by the British Establishment - in this case, at Cambridge University in the 1950s. The key elements in adding depth to the game were the standardisation of the pieces and playing surface, the development of a points scoring system, and giving the game a defensive element. The resulting game has been compared to a cross between chess and pool, with a 3-D element thrown in."

Also, from The Guardian archives: 5 January 1961: Peter Downes, tiddlywinks tycoon.