What was the circuit in round 2?
CREATE TABLE "calendar_winners" (
  "round" text,
  "circuit" text,
  "date" text,
  "class_a_winner" text,
  "class_b_winner" text,
  "class_c_winner" text,
  "class_d_winner" text
);
SELECT "circuit" FROM "calendar_winners" WHERE "round"='2';