What one-off 2010 Booker award honored 1970 novels missed after a rules change?

The one-off 2010 Booker award for novels published in 1970 was the Lost Man Booker Prize.

The prize arose from a change in Booker eligibility rules. Until 1970, the award recognized novels published in the preceding year; from 1971, it recognized books published during the award year. That transition left 1970 novels out of consideration entirely.

A longlist of 22 novels was assembled, followed by a public-vote shortlist of six. J. G. Farrell won with Troubles, receiving 38 percent of the vote. The award was announced 40 years after the novel’s publication and 30 years after Farrell’s death.

It is commonly confused with Booker of Bookers, a separate 1993 award that selected Salman Rushdie’s Midnight’s Children as the best Booker winner up to that time.