Which round has 4 clubs involved?
CREATE TABLE "team_distribution" (
  "round" text,
  "clubs_remaining" real,
  "clubs_involved" real,
  "winners_from_previous_round" text,
  "new_entries_this_round" text,
  "leagues_entering_at_this_round" text
);
SELECT "round" FROM "team_distribution" WHERE "clubs_involved"=4;