I will say the Pearl Harbor surprise (forget name of scenario) pulled off a couple of years ago made it more realistic. We did not know how the Japanese planes got to the island so quickly and in such dominant positions. Well thought out simulation of the surprise that the US experienced. We were scrambling from the very first minutes. It can be done, but only for a frame, then it loses it's mystery. Snapshot is better for an event like Y-29, but as Devil says you know it's coming and making the surprise up with rules kills the fun.