CREATE TABLE table_22673872_1 (rnd INT, winning_driver VARCHAR, track VARCHAR)

In what round did Al Unser win at Wisconsin State Fair Park Speedway?
SELECT MIN(rnd) FROM table_22673872_1 WHERE winning_driver = "Al Unser" AND track = "Wisconsin State Fair Park Speedway"
SELECT MIN("rnd") FROM "table_22673872_1" WHERE "Al Unser" = "winning_driver" AND "Wisconsin State Fair Park Speedway" = "track"