With all the things you have to pull together to catch fish on the fly... a cast, a drift, picking the right bug, and finding where the fish will be in the river... the luck factor is almost nil. Sure, you can be lucky and have good conditions (or not). But in the end, it's not a luck game. Two guys go for wild cutthroat trout during a mayfly hatch... one guy catches 12 fish on dry flies, the other gets blanked. Luck? Hardly.