Table schema:
CREATE TABLE table_20079931_4 (round VARCHAR, circuit_location VARCHAR, pole_position VARCHAR)

Question: 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"