Hey Spark, back in the 80s thru 90s total walleye population was between 60 to 80 million fish.... with so many mouths to feed they virtually attached everything passing by. Now populations are way down coupled with increased water clarity its just more difficult.... trolling becomes more effective just because of more ground being covered & baits presented to more fish.......Not to say casting is a lost are, lots of capts continue to cast exclusively , doing quite well.