Do all flies catch fish?

[billyspey]

Only flies you have confidence in will work !

[kengore]

Not all flies catch fish, but they only need to catch fisherman to be commercially successful.

[FishnDave]

I like Warren's response.

Its difficult to make generalizations sound like absolutes, because there are so many different fishing situations and species-specific fish behaviors that need to be considered. Some fish can be caught on a dry fly sitting motionless on the water surface, or on a nymph allowed to tumble freely downstream, or by imparting action that makes a fly look alive. Fly size and color are important, but the fish will tell you how they want it presented on any given day. Some days, every fly and presentation seems to work. Some days the fish are much more selective.