What is the highest Round, when the Opponent is Junior Pitbull?
CREATE TABLE "mixed_martial_arts_record" (
  "result" text,
  "record" text,
  "opponent" text,
  "method" text,
  "date" text,
  "round" real,
  "location" text,
  "notes" text
);
SELECT MAX("round") FROM "mixed_martial_arts_record" WHERE "opponent"='junior pitbull';