Complex sentence: Fifteen to One was a popular general knowledge quiz show on Channel 4 in the United Kingdom, that ran from 4 January 1988 to 19 December 2003 that had a reputation for being the toughest quiz on TV.
Split into simpler sentences: Fifteen to One was a popular general knowledge quiz show broadcast on Channel 4 in the United Kingdom. It ran from 4 January 1988 to 19 December 2003, and had a reputation for being the toughest quiz on TV.