Over the past two seasons, I tested various circle-hook sizes and styles in worm fishing for stream trout. If I allowed the fish time to swallow the bait, about 50 percent of the trout were jaw-hooked. The remaining fish were gut-hooked even though I followed the manufacturers' directions carefully-making no hard hooksets and letting the pulling fish hook themselves. Granted, these were small-stream trout, and my testing extended over a few dozen rather than several hundred fish. Circle hooks, I found, were a big improvement over standard bait hooks in terms of reduced gut-hooking, but they aren't as fail-safe as I'd been told.