What is Team 2, when Score is 2 - 1?
CREATE TABLE "round_of_16" (
  "team_1" text,
  "score" text,
  "team_2" text,
  "1st_round" text,
  "2nd_round" text
);
SELECT "team_2" FROM "round_of_16" WHERE "score"='2 - 1';