Combine soy sauce, vinegar, garlic and oregano; pour over chicken in large shallow baking pan. Turn chicken pieces over several times to coat both sides with sauce.
Arrange pieces in single layer, skin-side down. Cover pan with aluminum foil; seal edges tightly. Bake in 375 degree oven 20 minutes. Turn chicken pieces over; cover and bake 25 minutes longer, or until chicken is no longer pink in center.
Discard foil; brush chicken with pan drippings. Turn on broiler and place oven rack at top position for broiling. Broil chicken in pan drippings 5 minutes, or until skin is golden brown and crispy.