what is the venue when the score is 20½–11½?
CREATE TABLE "results" (
  "year" real,
  "venue" text,
  "location" text,
  "winning_team" text,
  "score" text,
  "u_s_captain" text,
  "international_captain" text
);
SELECT "venue" FROM "results" WHERE "score"='20½–11½';