How it works
The Cover Catcher is a pice of elastic 8' 4" that has a discrete clip on each end. The Cover Catcher works by laying the elastic strip between your box spring and mattress with each fastener just poking out. By fastening the top comforter with the clips, the blanket will not be able to slide too far to any one side of the bed.
Of course if the bed time battles are with a bed partner who is quite nocturnally determined to steal the sheets, then doubling or tripling up on The Cover Catcher is a good idea.