The pullover is unique among chest exercises since it is neither a form press or flye. It provides a unique stretch for the pecs from bottom to top, and also helps stretch the muscles in your rib cage. The pullover was a mainstay movement for lifters in the early days of bodybuilding.
Tips: Do this exercise in “cross bench” style, where you lie perpendicular to the bench and just set your upper back and shoulders resting on the bench. Drop your hips low and keep them there throughout the set. Take a deep breath as you stretch the weight back and down behind you. Keep a slight bend in the elbows at all times.