My box contains about halfnhalf, curved and straight. Most of the time I'm chirono fishing I can't tell if the fish prefer one or the other. Some days I do notice a better hooking ratio on the curved hook esp. the smaller bugs. Sometimes it depends on how aggressive the fish are feeding. When they're feeding more aggressively I do better with a straight hook. When they're feeding casually with soft takes the curved hooks works better. Just a few observations with too many variants to be science, but with enough mystery to keep me going back for more!