What's the difference between a single strap and a cross-pattern strap?

A single strap wraps once around the suitcase, which is fast to put on and adjust. A cross-pattern (X-shape) strap wraps both horizontally and vertically, which holds a cracked or overstuffed hard-shell together more reliably and makes the bag harder to mistake on the belt. Cross-pattern straps are heavier and slower to fit, so most reviewers recommend them specifically for checked hard-side luggage.