The traditional Mastermind match for the best losers from the first round takes place tonight at Liverpool University, in this fourth and last of the semi-finals. The contenders come from Merseyside, Bolton, Manchester and York - a truly Northern occasion.The contenders are:Jolyon Coombs, stage manager - Commedia dell'ArteRosemary James, teacher - Life and works of Frederick RolfeFrank Lynch, teacher - European history, 1900-1945Anthony Martin, librarian - Greek mythology