It's a combination of both, but I have to say the skill side outways the luck part of it. Plenty of scouting, multiple stand locations, and common knowledge of your area as well as knowledge of the deer in your area greatly increase your chances of taking down the big, wary, nocturnal bucks. Keeping your scent to a minimum, playing your wind direction properly and the ability to make the shot when offered is skill, not luck. Luck is when you hear about those select few lighting up a cig in the woods and a monster comes trotting back to his bedding area or chasing a doe and he lifts his shotgun/crossbow and takes him down. There is a fine line between those who get lucky and those who consistantly take down big bucks year after year.