You're definitely not wrong, its generally the fastest. Efficient is a bit of a loaded worded in these contexts, and I feel as though when discussiing algorithms, unless otherwise specified, the assumption is you're discussing worst-case efficiency (because while worst case isn't always the most useful metric, is usually the most easily defined and derived one). And randomizing data doesn't necessarily guarantee that you won't still land on a worst-case starting order (as is the nature of randomness). As I said though, that is an entirely nitpicky point.