Who was the pregame host before 1992 when there was a play by play of Bob Irving?
CREATE TABLE "1990s" (
  "year" real,
  "network" text,
  "play_by_play" text,
  "colour_commentator_s" text,
  "pregame_host" text
);
SELECT "pregame_host" FROM "1990s" WHERE "year"<1992 AND "play_by_play"='bob irving';