CREATE TABLE table_51498 ("Pick" FLOAT, "Round" CLOB, "Player" CLOB, "Position" CLOB, "School" CLOB)

What's the lowest pick for a defensive back at Drake?
SELECT MIN("Pick") FROM table_51498 WHERE "Position" = 'defensive back' AND "School" = 'drake'
SELECT MIN("Pick") FROM "table_51498" WHERE "Position" = 'defensive back' AND "School" = 'drake'