What competition had its first match on December 20, 2007?
CREATE TABLE "overall" (
  "competition" text,
  "started_round" text,
  "final_position" text,
  "final_round" text,
  "first_match" text,
  "last_match" text
);
SELECT "competition" FROM "overall" WHERE "first_match"='december 20, 2007';