Irons such as the Ping Eye 2 (immediately below) are more forgiving on mishits because perimeter weight distribution reduces the degree of twist by the club head and enlarges the sweet spot by spreading the weight out around the head. By comparison, forged clubs twist more because of less efficient weight distribution; thus a mishit is more apt to reduce distance and alter direction.
On an ideal club path, a ball mishit on the heel of an iron with a closed face will lose distance and probably curve left.
A ball struck by an iron in the center of the sweet spot will have only backspin and will follow a straight path to the target.
When the ball is mishit on the toe of the iron, with the face open, the ball will lose distance and probably curve right.