On average, any lossless compression scheme must have >= 1x compression. Lossy compression schemes can have less (since they're discarding information), and los

On average, any lossless compression scheme must have >= 1x compression. Lossy compression schemes can have less (since they're discarding information), and lossless compression schemes certainly can average out to > 1x (this is trivially observable by taking any 1x-average scheme and adding a fixed-length header to the output).