They work by using the body of the ride-on mower to push over the tall grass therefore allowing the grass to be folded over and hence the 90 degree angle of the blade cuts the horizontal grass.
This is by no means all that it can do.
It will cut thick shrub and flora and most anything that the mower can push over. It creates a vacuum type suction which allows the blade to keep cutting the grass and creating a mulch finer than any other.
There is no carpet affect and it will not simply ride over the grass.
When the 90 degree part of the blade has completed its job the horizontal part of the blade will trim the grass to the desired length. We feel that there is no comparison to this blade and to say there has been no different type of cutting motion for a mower blade would be an understatement you only need to go over the grass in just one motion,forward.