CREATE TABLE table_44942 ("Round" FLOAT, "Pick" FLOAT, "Player" TEXT, "Position" TEXT, "School/Club Team" TEXT)

Name the Round which has a Position of defensive back and corey chavous?
SELECT MIN("Round") FROM table_44942 WHERE "Position" = 'defensive back' AND "Player" = 'corey chavous'
SELECT MIN("Round") FROM "table_44942" WHERE "Player" = 'corey chavous' AND "Position" = 'defensive back'