The compression method of impact attentuation would be the best if everything was like it was in the movies. The movie industry uses massive 1 to 2 story thick airbags shaped like mattresses, with velcro flaps that open to release some of the inside air upon impact to gradually reduce the speed and rate of descent until fully stopped, to keep stunt people safe from high elevation falls. It's a great form of fall protection that's hardly practical and adaptable to daily life, or real life scenarios effectively and efficiently. 

For purposes of playground safety surfacing, those that utilize compression alone are monolithic or unitary surfaces that have varying degrees of compression impact attentuation, which tend to return to their original position immediately after initial impact. This takes all the same kinetic energy absorbed during compression and immediately releases it by pushing back upward, against the impacting body as it continues to fall downward into the same material, with no further impact absorption.

This essentially amplifies or increases the nature and severity or fall injury and test analysis has shown fall impacts on surfaces like Pour-In-Place (PIP) are 444% to 700% more likely to result in traumatic brain injury (TBI) or death vs your average playground rubber mulch (and we've tested up to 100% safer than other rubber mulches!). 

Part of what makes out rubber mulch so effective and safe for fall impact injury protection is it initially uses the dispersion method to cause brief decelleration before the secondary compression method brings the impacting body to a stop, without returning to its original position, thereby completely absorbing the kinetic energy of an impact the best. The only thing left to do is rake to level out the area of impact, which is probably a whole lot better than a trip to the emergency room!