Power Raking is a great way to remove dead debris and crust that builds up on a lawn over Winter. It's also a gentle way to remove a small amount of thatch from the lawn, without causing the significant damage that dethatching can cause. It's also a great way to thicken up bentgrass lawns, since Power Raking slices the surface stolons and stimulates new growth, thickening the lawn.
Power Raking generally involves using fixed knife type blades that slice the thatch instead of ripping it out. Using a dethatching machine, it is set to high so that the blades just skim the surface. Unlike dethatching, Power Raking doesn't cause extensive damage, so the lawn recovers rapidly and maintains its density.
Power Raking can be done in Spring or Fall. If you're looking to remove Winter debris, it is recommended to do it before the lawn starts growing to avoid setting the lawn back during critical Spring time growth.