CREATE TABLE "indianapolis_colts_draft_history" (
  "round" real,
  "pick_num" real,
  "overall" real,
  "name" text,
  "position" text,
  "college" text
);

Question: What's the highest round for a defensive tackle position?
SQL: SELECT MAX("round") FROM "indianapolis_colts_draft_history" WHERE "position"='defensive tackle';