user: Question: Who was the pregame host before 1992 when there was a play by play of Bob Irving?
Columns: ['Year', 'Network', 'Play-by-play', 'Colour commentator(s)', 'Pregame host']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1999.0, 'CBC', 'Chris Cuthbert', 'Chris Walby', 'Brian Williams']
SQL:

assistant: SELECT "Pregame host" FROM "Table" WHERE "Year" < 1992.0 AND "Play-by-play" = 'Bob Irving';