CREATE TABLE table_6156 ("Round" FLOAT, "Player" TEXT, "Position" TEXT, "Nationality" TEXT, "College/Junior/Club Team" TEXT)

What is the total number of rounds that Center position Denis Arkhipov have?
SELECT COUNT("Round") FROM table_6156 WHERE "Position" = 'center' AND "Player" = 'denis arkhipov'
SELECT COUNT("Round") FROM "table_6156" WHERE "Player" = 'denis arkhipov' AND "Position" = 'center'