CREATE TABLE table_20079931_4 (round VARCHAR(255), circuit_location VARCHAR(255), pole_position VARCHAR(255))
How many rounds were there in Karlskoga Motorstadion with Roger Eriksson at the pole position?
    
SQL: SELECT COUNT(round) FROM table_20079931_4 WHERE circuit_location = "Karlskoga Motorstadion" AND pole_position = "Roger Eriksson"